From 084bc5f315e40ca7a7c23a480c0a6dfa1d1ace54 Mon Sep 17 00:00:00 2001
From: "dependabot[bot]" <49699333+dependabot[bot]@users.noreply.github.com>
Date: Tue, 29 Sep 2026 13:29:39 +0200
Subject: [PATCH] build(deps): bump undici from 7.29.0 to 7.30.0 (#1425)

Co-authored-by: Fernandez Ludovic <ldez@users.noreply.github.com>
---
 dist/post_run/index.js | 1225 ++++++++++++++++++++++++++++++----------
 dist/run/index.js      | 1225 ++++++++++++++++++++++++++++++----------
 package-lock.json      |    6 +-
 3 files changed, 1843 insertions(+), 613 deletions(-)

diff --git a/dist/post_run/index.js b/dist/post_run/index.js
index 78f8856..9e36060 100644
--- a/dist/post_run/index.js
+++ b/dist/post_run/index.js
@@ -34858,11 +34858,32 @@ class Request {
     }
   }
 
-  onUpgrade (statusCode, headers, socket) {
+  /**
+   * @param {number} statusCode
+   * @param {Buffer[]|string[]} headers
+   * @param {import('node:stream').Duplex} socket
+   * @param {string} [statusText]
+   */
+  onUpgrade (statusCode, headers, socket, statusText = '') {
+    this.onFinally()
+
     assert(!this.aborted)
     assert(!this.completed)
 
-    return this[kHandler].onUpgrade(statusCode, headers, socket)
+    if (channels.headers.hasSubscribers) {
+      channels.headers.publish({ request: this, response: { statusCode, headers, statusText } })
+    }
+
+    const result = this[kHandler].onUpgrade(statusCode, headers, socket)
+
+    if (!this.aborted) {
+      this.completed = true
+      if (channels.trailers.hasSubscribers) {
+        channels.trailers.publish({ request: this, trailers: [] })
+      }
+    }
+
+    return result
   }
 
   onComplete (trailers) {
@@ -37144,14 +37165,16 @@ function defaultFactory (origin, opts) {
 }
 
 class BalancedPool extends PoolBase {
-  constructor (upstreams = [], { factory = defaultFactory, ...opts } = {}) {
+  constructor (upstreams = [], { factory = defaultFactory, connect, tls, ...opts } = {}) {
     if (typeof factory !== 'function') {
       throw new InvalidArgumentError('factory must be a function.')
     }
 
     super(opts)
 
-    this[kOptions] = { ...util.deepClone(opts) }
+    if (connect && typeof connect !== 'function') connect = { ...connect }
+    if (tls && typeof tls !== 'function') tls = { ...tls }
+    this[kOptions] = { ...util.deepClone(opts), connect, tls }
     this[kOptions].interceptors = opts.interceptors
       ? { ...opts.interceptors }
       : undefined
@@ -37391,8 +37414,14 @@ function lazyllhttp () {
 
   let mod
 
-  // We disable wasm SIMD on ppc64 as it seems to be broken on Power 9 architectures.
-  let useWasmSIMD = process.arch !== 'ppc64'
+  // We disable wasm SIMD on older versions of Node.js on ppc64 that are broken on Power >=9 architectures.
+  let useWasmSIMD = true
+  if (process.arch === 'ppc64') {
+    const [major, minor] = process.versions.node.split('.').map(n => parseInt(n, 10))
+    if (major < 24 || (major === 24 && minor < 12)) {
+      useWasmSIMD = false
+    }
+  }
   // The Env Variable UNDICI_NO_WASM_SIMD allows explicitly overriding the default behavior
   if (process.env.UNDICI_NO_WASM_SIMD === '1') {
     useWasmSIMD = false
@@ -37843,7 +37872,7 @@ class Parser {
    * @param {Buffer} head
    */
   onUpgrade (head) {
-    const { upgrade, client, socket, headers, statusCode } = this
+    const { upgrade, client, socket, headers, statusCode, statusText } = this
 
     assert(upgrade)
     assert(client[kSocket] === socket)
@@ -37878,8 +37907,9 @@ class Parser {
     client.emit('disconnect', client[kUrl], [client], new InformationalError('upgrade'))
 
     try {
-      request.onUpgrade(statusCode, headers, socket)
+      request.onUpgrade(statusCode, headers, socket, statusText)
     } catch (err) {
+      util.errorRequest(client, request, err)
       util.destroy(socket, err)
     }
 
@@ -38334,7 +38364,7 @@ function onSocketClose () {
 
 function clearIdleSocketValidation (socket) {
   if (socket[kIdleSocketValidationTimeout]) {
-    clearTimeout(socket[kIdleSocketValidationTimeout])
+    clearImmediate(socket[kIdleSocketValidationTimeout])
     socket[kIdleSocketValidationTimeout] = null
   }
 
@@ -38343,15 +38373,23 @@ function clearIdleSocketValidation (socket) {
 
 function scheduleIdleSocketValidation (client, socket) {
   socket[kIdleSocketValidation] = 1
-  socket[kIdleSocketValidationTimeout] = setTimeout(() => {
+  // Yield to the check phase (after poll) so unsolicited bytes / FIN / RST
+  // already pending on this idle keep-alive socket are processed before the
+  // next request is written (GHSA-35p6-xmwp-9g52).
+  //
+  // setTimeout(0) pays Node's ~1ms timer floor on every sequential reuse
+  // (#5493). setImmediate avoids that, but an *unref'd* Immediate lets poll
+  // block for ~500ms when the event loop is otherwise idle (#5600 / #5606).
+  // A ref'd Immediate both keeps the pending request alive and makes poll
+  // return immediately — the hybrid those issues asked for.
+  socket[kIdleSocketValidationTimeout] = setImmediate(() => {
     socket[kIdleSocketValidationTimeout] = null
     socket[kIdleSocketValidation] = 2
 
     if (client[kSocket] === socket && !socket.destroyed) {
       client[kResume]()
     }
-  }, 0)
-  socket[kIdleSocketValidationTimeout].unref?.()
+  })
 }
 
 /**
@@ -39069,7 +39107,9 @@ const {
   RequestAbortedError,
   SocketError,
   InformationalError,
-  InvalidArgumentError
+  InvalidArgumentError,
+  HeadersTimeoutError,
+  BodyTimeoutError
 } = __nccwpck_require__(68707)
 const {
   kUrl,
@@ -39094,6 +39134,7 @@ const {
   kHTTPContext,
   kClosed,
   kBodyTimeout,
+  kHeadersTimeout,
   kEnableConnectProtocol,
   kRemoteSettings,
   kHTTP2Stream,
@@ -39280,7 +39321,11 @@ function resumeH2 (client) {
   const socket = client[kSocket]
 
   if (socket?.destroyed === false) {
-    if (client[kSize] === 0 || client[kMaxConcurrentStreams] === 0) {
+    // Only let the process exit when there is genuinely nothing outstanding.
+    // Unreffing because the peer advertised MAX_CONCURRENT_STREAMS = 0 left
+    // queued requests with nothing holding the event loop open, so the process
+    // could exit with status 0 while an awaited request never settled.
+    if (client[kSize] === 0) {
       socket.unref()
       client[kHTTP2Session].unref()
     } else {
@@ -39375,6 +39420,36 @@ function onHttp2SessionEnd () {
  * @this {import('http2').ClientHttp2Session}
  * @param {number} errorCode
  */
+// Backport of #5410 and #5569. HTTP/2 multiplexes, so requests complete out of
+// order; advancing kRunningIdx blindly retired whichever request happened to
+// sit at the head instead of the one that actually finished, which both lost
+// requests and left phantom running slots behind.
+function completeRequest (client, request, resetPendingIdx = false) {
+  const queue = client[kQueue]
+  const runningIdx = client[kRunningIdx]
+
+  // In-order completion: clear the request and advance without splicing.
+  // The client's resume loop compacts cleared slots once the index grows.
+  if (runningIdx < client[kPendingIdx] && queue[runningIdx] === request) {
+    queue[runningIdx] = null
+    client[kRunningIdx] = runningIdx + 1
+    return
+  }
+
+  const index = queue.indexOf(request, runningIdx)
+
+  if (index === -1 || index >= client[kPendingIdx]) {
+    return
+  }
+
+  queue.splice(index, 1)
+  client[kPendingIdx]--
+
+  if (resetPendingIdx && client[kPendingIdx] < client[kRunningIdx]) {
+    client[kPendingIdx] = client[kRunningIdx]
+  }
+}
+
 function onHttp2SessionGoAway (errorCode) {
   // TODO(mcollina): Verify if GOAWAY implements the spec correctly:
   // https://datatracker.ietf.org/doc/html/rfc7540#section-6.8
@@ -39396,7 +39471,9 @@ function onHttp2SessionGoAway (errorCode) {
   if (client[kRunningIdx] < client[kQueue].length) {
     const request = client[kQueue][client[kRunningIdx]]
     client[kQueue][client[kRunningIdx]++] = null
-    util.errorRequest(client, request, err)
+    if (request != null) {
+      util.errorRequest(client, request, err)
+    }
     client[kPendingIdx] = client[kRunningIdx]
   }
 
@@ -39429,7 +39506,9 @@ function onHttp2SessionClose () {
     const requests = client[kQueue].splice(client[kRunningIdx])
     for (let i = 0; i < requests.length; i++) {
       const request = requests[i]
-      util.errorRequest(client, request, err)
+      if (request != null) {
+        util.errorRequest(client, request, err)
+      }
     }
   }
 }
@@ -39477,7 +39556,10 @@ function shouldSendContentLength (method) {
 }
 
 function writeH2 (client, request) {
-  const requestTimeout = request.bodyTimeout ?? client[kBodyTimeout]
+  // Time to the response headers, then time between body chunks. Using
+  // bodyTimeout for both made headersTimeout a no-op over HTTP/2.
+  const headersTimeout = request.headersTimeout ?? client[kHeadersTimeout]
+  const bodyTimeout = request.bodyTimeout ?? client[kBodyTimeout]
   const session = client[kHTTP2Session]
   const { method, path, host, upgrade, expectContinue, signal, protocol, headers: reqHeaders } = request
   let { body } = request
@@ -39544,6 +39626,7 @@ function writeH2 (client, request) {
 
       // We move the running index to the next request
       client[kOnError](err)
+      completeRequest(client, request)
       client[kResume]()
     }
 
@@ -39591,14 +39674,18 @@ function writeH2 (client, request) {
 
       stream = session.request(headers, { endStream: false, signal })
       stream[kHTTP2Stream] = true
+      ++session[kOpenStreams]
 
       stream.once('response', (headers, _flags) => {
         const { [HTTP2_HEADER_STATUS]: statusCode, ...realHeaders } = headers
 
-        request.onUpgrade(statusCode, parseH2Headers(realHeaders), stream)
-
-        ++session[kOpenStreams]
-        client[kQueue][client[kRunningIdx]++] = null
+        try {
+          request.onUpgrade(statusCode, parseH2Headers(realHeaders), stream)
+        } catch (err) {
+          abort(err)
+          return
+        }
+        completeRequest(client, request)
       })
 
       stream.on('error', () => {
@@ -39615,7 +39702,7 @@ function writeH2 (client, request) {
         if (session[kOpenStreams] === 0) session.unref()
       })
 
-      stream.setTimeout(requestTimeout)
+      stream.setTimeout(headersTimeout)
       return true
     }
 
@@ -39626,18 +39713,24 @@ function writeH2 (client, request) {
     // We disabled endStream to allow the user to write to the stream
     stream = session.request(headers, { endStream: false, signal })
     stream[kHTTP2Stream] = true
+    ++session[kOpenStreams]
     stream.on('response', headers => {
       const { [HTTP2_HEADER_STATUS]: statusCode, ...realHeaders } = headers
 
-      request.onUpgrade(statusCode, parseH2Headers(realHeaders), stream)
-      ++session[kOpenStreams]
-      client[kQueue][client[kRunningIdx]++] = null
+      try {
+        request.onUpgrade(statusCode, parseH2Headers(realHeaders), stream)
+      } catch (err) {
+        abort(err)
+        return
+      }
+      completeRequest(client, request)
     })
+    stream.on('error', abort)
     stream.once('close', () => {
       session[kOpenStreams] -= 1
       if (session[kOpenStreams] === 0) session.unref()
     })
-    stream.setTimeout(requestTimeout)
+    stream.setTimeout(headersTimeout)
 
     return true
   }
@@ -39738,7 +39831,7 @@ function writeH2 (client, request) {
 
   // Increment counter as we have new streams open
   ++session[kOpenStreams]
-  stream.setTimeout(requestTimeout)
+  stream.setTimeout(headersTimeout)
 
   // Track whether we received a response (headers)
   let responseReceived = false
@@ -39747,6 +39840,7 @@ function writeH2 (client, request) {
     const { [HTTP2_HEADER_STATUS]: statusCode, ...realHeaders } = headers
     request.onResponseStarted()
     responseReceived = true
+    stream.setTimeout(bodyTimeout)
 
     // Due to the stream nature, it is possible we face a race condition
     // where the stream has been assigned, but the request has been aborted
@@ -39781,14 +39875,13 @@ function writeH2 (client, request) {
         request.onComplete({})
       }
 
-      client[kQueue][client[kRunningIdx]++] = null
+      completeRequest(client, request)
       client[kResume]()
     } else {
       // Stream ended without receiving a response - this is an error
       // (e.g., server destroyed the stream before sending headers)
       abort(new InformationalError('HTTP/2: stream half-closed (remote)'))
-      client[kQueue][client[kRunningIdx]++] = null
-      client[kPendingIdx] = client[kRunningIdx]
+      completeRequest(client, request, true)
       client[kResume]()
     }
   })
@@ -39799,6 +39892,14 @@ function writeH2 (client, request) {
     if (session[kOpenStreams] === 0) {
       session.unref()
     }
+
+    // A stream can close without ever emitting 'end' or 'error': a peer's
+    // RST_STREAM(CANCEL) received before the response is reported by Node as a
+    // bare 'close', and destroying the stream unenrolls its timeout, so no
+    // 'timeout' follows either. Nothing else would ever settle this request.
+    if (!request.aborted && !request.completed) {
+      abort(new InformationalError('HTTP/2: stream closed before the response was complete'))
+    }
   })
 
   stream.once('error', function (err) {
@@ -39816,7 +39917,9 @@ function writeH2 (client, request) {
   })
 
   stream.on('timeout', () => {
-    const err = new InformationalError(`HTTP/2: "stream timeout after ${requestTimeout}"`)
+    const err = responseReceived
+      ? new BodyTimeoutError(`HTTP/2: "body timeout after ${bodyTimeout}"`)
+      : new HeadersTimeoutError(`HTTP/2: "headers timeout after ${headersTimeout}"`)
     stream.removeAllListeners('data')
     session[kOpenStreams] -= 1
 
@@ -40438,7 +40541,9 @@ class Client extends DispatcherBase {
       const requests = this[kQueue].splice(this[kPendingIdx])
       for (let i = 0; i < requests.length; i++) {
         const request = requests[i]
-        util.errorRequest(this, request, err)
+        if (request != null) {
+          util.errorRequest(this, request, err)
+        }
       }
 
       const callback = () => {
@@ -40477,7 +40582,9 @@ function onError (client, err) {
 
     for (let i = 0; i < requests.length; i++) {
       const request = requests[i]
-      util.errorRequest(client, request, err)
+      if (request != null) {
+        util.errorRequest(client, request, err)
+      }
     }
     assert(client[kSize] === 0)
   }
@@ -42786,6 +42893,13 @@ class CacheHandler {
     }
 
     const cacheControlHeader = resHeaders['cache-control']
+    const cacheControlDirectives = cacheControlHeader ? parseCacheControlHeader(cacheControlHeader) : {}
+
+    if (revalidationResponseDisallowsCachedReuse(this.#cacheType, resHeaders, cacheControlDirectives)) {
+      deleteCachedValue(this.#store, this.#cacheKey)
+      return downstreamOnHeaders()
+    }
+
     const heuristicallyCacheable = resHeaders['last-modified'] && arrayIncludes(HEURISTICALLY_CACHEABLE_STATUS_CODES, statusCode)
     if (
       !cacheControlHeader &&
@@ -42802,8 +42916,7 @@ class CacheHandler {
       return downstreamOnHeaders()
     }
 
-    const cacheControlDirectives = cacheControlHeader ? parseCacheControlHeader(cacheControlHeader) : {}
-    if (!canCacheResponse(this.#cacheType, statusCode, resHeaders, cacheControlDirectives, this.#cacheKey.headers)) {
+    if (!canCacheResponse(this.#cacheType, this.#cacheKey.method, statusCode, resHeaders, cacheControlDirectives, this.#cacheKey.headers)) {
       if (statusCode === 304 && (cacheControlHeader || revalidationResponseDisallowsCachedReuse(this.#cacheType, resHeaders, cacheControlDirectives))) {
         deleteCachedValue(this.#store, this.#cacheKey)
       }
@@ -43044,7 +43157,10 @@ function deleteCachedValueIfNotModified (statusCode, store, cacheKey) {
  */
 function revalidationResponseDisallowsCachedReuse (cacheType, resHeaders, cacheControlDirectives) {
   return cacheControlDirectives['no-store'] === true ||
-    (cacheType === 'shared' && cacheControlDirectives.private === true) ||
+    (cacheType === 'shared' && (
+      cacheControlDirectives.private === true ||
+      Object.hasOwn(resHeaders, 'set-cookie')
+    )) ||
     (resHeaders.vary ? isInvalidOrWildcardVaryHeader(resHeaders.vary) : false)
 }
 
@@ -43052,12 +43168,16 @@ function revalidationResponseDisallowsCachedReuse (cacheType, resHeaders, cacheC
  * @see https://www.rfc-editor.org/rfc/rfc9111.html#name-storing-responses-to-authen
  *
  * @param {import('../../types/cache-interceptor.d.ts').default.CacheOptions['type']} cacheType
+ * @param {string} method
  * @param {number} statusCode
  * @param {import('../../types/header.d.ts').IncomingHttpHeaders} resHeaders
  * @param {import('../../types/cache-interceptor.d.ts').default.CacheControlDirectives} cacheControlDirectives
  * @param {import('../../types/header.d.ts').IncomingHttpHeaders} [reqHeaders]
  */
-function canCacheResponse (cacheType, statusCode, resHeaders, cacheControlDirectives, reqHeaders) {
+function canCacheResponse (cacheType, method, statusCode, resHeaders, cacheControlDirectives, reqHeaders) {
+  if (!arrayIncludes(util.safeHTTPMethods, method)) {
+    return false
+  }
   // Status code must be final and understood.
   if (statusCode < 200 || arrayIncludes(NOT_UNDERSTOOD_STATUS_CODES, statusCode)) {
     return false
@@ -43078,7 +43198,10 @@ function canCacheResponse (cacheType, statusCode, resHeaders, cacheControlDirect
     return false
   }
 
-  if (cacheType === 'shared' && cacheControlDirectives.private === true) {
+  if (cacheType === 'shared' && (
+    cacheControlDirectives.private === true ||
+    Object.hasOwn(resHeaders, 'set-cookie')
+  )) {
     return false
   }
 
@@ -44303,6 +44426,55 @@ function validatePartialResponseContentLength (headers, range, statusCode, retry
   }
 }
 
+// A stable controller handed to the downstream handler for the lifetime of the
+// request. Each transparent retry/resume is a separate dispatch with its own
+// connection controller. The proxy always forwards to the active connection
+// while preserving a downstream pause across controller replacement.
+class RetryController {
+  #paused = false
+  #target = null
+
+  set target (target) {
+    this.#target = target
+    if (this.#paused) {
+      target?.pause()
+    }
+  }
+
+  get target () { return this.#target }
+
+  pause () {
+    this.#paused = true
+    this.#target?.pause()
+  }
+
+  resume () {
+    this.#paused = false
+    this.#target?.resume()
+  }
+
+  abort (reason) {
+    this.#target?.abort(reason)
+  }
+
+  get paused () { return this.#paused || (this.#target?.paused ?? false) }
+  get aborted () { return this.#target?.aborted ?? false }
+  get reason () { return this.#target?.reason ?? null }
+  get rawHeaders () { return this.#target?.rawHeaders ?? null }
+  set rawHeaders (value) {
+    if (this.#target) {
+      this.#target.rawHeaders = value
+    }
+  }
+
+  get rawTrailers () { return this.#target?.rawTrailers ?? null }
+  set rawTrailers (value) {
+    if (this.#target) {
+      this.#target.rawTrailers = value
+    }
+  }
+}
+
 class RetryHandler {
   constructor (opts, { dispatch, handler }) {
     const { retryOptions, ...dispatchOpts } = opts
@@ -44357,14 +44529,23 @@ class RetryHandler {
     this.start = 0
     this.end = null
     this.etag = null
+    this.controllerProxy = new RetryController()
   }
 
   onResponseStartWithRetry (controller, statusCode, headers, statusMessage, err) {
     if (this.retryOpts.throwOnError) {
       // Preserve old behavior for status codes that are not eligible for retry
       if (this.retryOpts.statusCodes.includes(statusCode) === false) {
-        this.headersSent = true
-        this.handler.onResponseStart?.(controller, statusCode, headers, statusMessage)
+        if (this.headersSent) {
+          // The downstream handler already received the response from an
+          // earlier attempt. Forwarding this response would replace the
+          // downstream body and leave the original body pending forever.
+          this.handler.onResponseError?.(this.controllerProxy, err)
+        } else {
+          this.headersSent = true
+          this.checkpointResponseEnd(headers)
+          this.handler.onResponseStart?.(this.controllerProxy, statusCode, headers, statusMessage)
+        }
       } else {
         this.error = err
       }
@@ -44374,14 +44555,23 @@ class RetryHandler {
 
     if (isDisturbed(this.opts.body)) {
       this.headersSent = true
-      this.handler.onResponseStart?.(controller, statusCode, headers, statusMessage)
+      this.checkpointResponseEnd(headers)
+      this.handler.onResponseStart?.(this.controllerProxy, statusCode, headers, statusMessage)
       return
     }
 
     function shouldRetry (passedErr) {
       if (passedErr) {
-        this.headersSent = true
-        this.handler.onResponseStart?.(controller, statusCode, headers, statusMessage)
+        if (this.headersSent) {
+          // The downstream handler already received the response from an
+          // earlier attempt. Forwarding this response would replace the
+          // downstream body and leave the original body pending forever.
+          this.handler.onResponseError?.(this.controllerProxy, passedErr)
+        } else {
+          this.headersSent = true
+          this.checkpointResponseEnd(headers)
+          this.handler.onResponseStart?.(this.controllerProxy, statusCode, headers, statusMessage)
+        }
         controller.resume()
         return
       }
@@ -44401,14 +44591,29 @@ class RetryHandler {
     )
   }
 
-  onRequestStart (controller, context) {
-    if (!this.headersSent) {
-      this.handler.onRequestStart?.(controller, context)
+  checkpointResponseEnd (headers) {
+    if (this.end == null && this.opts.method !== 'HEAD') {
+      const contentLength = headers['content-length']
+      this.end = contentLength != null ? Number(contentLength) - 1 : null
+
+      assert(
+        this.end == null || Number.isFinite(this.end),
+        'invalid content-length'
+      )
+
+      this.resume = this.end != null
     }
   }
 
-  onRequestUpgrade (controller, statusCode, headers, socket) {
-    this.handler.onRequestUpgrade?.(controller, statusCode, headers, socket)
+  onRequestStart (controller, context) {
+    this.controllerProxy.target = controller
+    if (!this.headersSent) {
+      this.handler.onRequestStart?.(this.controllerProxy, context)
+    }
+  }
+
+  onRequestUpgrade (_controller, statusCode, headers, socket) {
+    this.handler.onRequestUpgrade?.(this.controllerProxy, statusCode, headers, socket)
   }
 
   static [kRetryHandlerDefaultRetry] (err, { state, opts }, cb) {
@@ -44521,8 +44726,12 @@ class RetryHandler {
 
       const { start, size, end = size ? size - 1 : null } = contentRange
 
-      assert(this.start === start, 'content-range mismatch')
-      assert(this.end == null || this.end === end, 'content-range mismatch')
+      if (this.start !== start || (this.end != null && this.end !== end)) {
+        throw new RequestRetryError('Content-Range mismatch', statusCode, {
+          headers,
+          data: { count: this.retryCount }
+        })
+      }
 
       return
     }
@@ -44535,7 +44744,7 @@ class RetryHandler {
         if (range == null) {
           this.headersSent = true
           this.handler.onResponseStart?.(
-            controller,
+            this.controllerProxy,
             statusCode,
             headers,
             statusMessage
@@ -44584,7 +44793,7 @@ class RetryHandler {
 
       this.headersSent = true
       this.handler.onResponseStart?.(
-        controller,
+        this.controllerProxy,
         statusCode,
         headers,
         statusMessage
@@ -44597,30 +44806,30 @@ class RetryHandler {
     }
   }
 
-  onResponseData (controller, chunk) {
+  onResponseData (_controller, chunk) {
     if (this.error) {
       return
     }
 
     this.start += chunk.length
 
-    this.handler.onResponseData?.(controller, chunk)
+    this.handler.onResponseData?.(this.controllerProxy, chunk)
   }
 
-  onResponseEnd (controller, trailers) {
+  onResponseEnd (_controller, trailers) {
     if (this.error && this.retryOpts.throwOnError) {
       throw this.error
     }
 
     if (!this.error) {
       this.retryCount = 0
-      return this.handler.onResponseEnd?.(controller, trailers)
+      return this.handler.onResponseEnd?.(this.controllerProxy, trailers)
     }
 
-    this.retry(controller)
+    this.retry()
   }
 
-  retry (controller) {
+  retry () {
     if (this.start !== 0) {
       const headers = { range: `bytes=${this.start}-${this.end ?? ''}` }
 
@@ -44642,23 +44851,23 @@ class RetryHandler {
       this.retryCountCheckpoint = this.retryCount
       this.dispatch(this.opts, this)
     } catch (err) {
-      this.handler.onResponseError?.(controller, err)
+      this.handler.onResponseError?.(this.controllerProxy, err)
     }
   }
 
   onResponseError (controller, err) {
-    if (controller?.aborted || isDisturbed(this.opts.body)) {
-      this.handler.onResponseError?.(controller, err)
+    if (controller?.aborted || isDisturbed(this.opts.body) || (this.headersSent && !this.resume)) {
+      this.handler.onResponseError?.(this.controllerProxy, err)
       return
     }
 
     function shouldRetry (returnedErr) {
       if (!returnedErr) {
-        this.retry(controller)
+        this.retry()
         return
       }
 
-      this.handler?.onResponseError?.(controller, returnedErr)
+      this.handler?.onResponseError?.(this.controllerProxy, returnedErr)
     }
 
     // We reconcile in case of a mix between network errors
@@ -45038,7 +45247,10 @@ function staleResponseRequiresRevalidation (result, cacheType) {
  * @returns {boolean}
  */
 function revalidationResponseDisallowsCachedReuse (cacheType, headers) {
-  if (headers.vary && isInvalidOrWildcardVaryHeader(headers.vary)) {
+  if (
+    (headers.vary && isInvalidOrWildcardVaryHeader(headers.vary)) ||
+    (cacheType === 'shared' && Object.hasOwn(headers, 'set-cookie'))
+  ) {
     return true
   }
 
@@ -45297,6 +45509,17 @@ function handleResult (
     return handleUncachedResponse(dispatch, globalOpts, cacheKey, handler, opts, reqCacheControl)
   }
 
+  // Shared stores may outlive the Undici version that wrote them. Do not
+  // re-serve a Set-Cookie header from an existing shared-cache entry.
+  if (globalOpts.type === 'shared' && Object.hasOwn(result.headers, 'set-cookie')) {
+    if (util.isStream(result.body)) {
+      result.body.on('error', nop).destroy()
+    }
+
+    deleteCachedValue(globalOpts.store, cacheKey)
+    return handleUncachedResponse(dispatch, globalOpts, cacheKey, handler, opts, reqCacheControl)
+  }
+
   const now = Date.now()
   if (now > result.deleteAt) {
     // Response is expired, cache store shouldn't have given this to us
@@ -45495,6 +45718,11 @@ module.exports = (opts = {}) => {
        * @type {import('../../types/cache-interceptor.d.ts').default.CacheKey}
        */
       const cacheKey = makeCacheKey(opts)
+
+      if (!arrayIncludes(util.safeHTTPMethods, opts.method)) {
+        return dispatch(opts, new CacheHandler(globalOpts, cacheKey, handler))
+      }
+
       const result = store.get(cacheKey)
 
       if (result && typeof result.then === 'function') {
@@ -45532,7 +45760,8 @@ module.exports = (opts = {}) => {
 
 
 const { createInflate, createGunzip, createBrotliDecompress, createZstdDecompress } = __nccwpck_require__(38522)
-const { pipeline } = __nccwpck_require__(57075)
+const { pipeline, Transform: TransformStream } = __nccwpck_require__(57075)
+const { InvalidArgumentError, ResponseExceededMaxSizeError } = __nccwpck_require__(68707)
 const DecoratorHandler = __nccwpck_require__(58155)
 const { runtimeFeatures } = __nccwpck_require__(313)
 
@@ -45540,6 +45769,60 @@ const { runtimeFeatures } = __nccwpck_require__(313)
 /** @typedef {import('node:stream').Transform} Controller */
 /** @typedef {Transform&import('node:zlib').Zlib} DecompressorStream */
 
+class DecompressController {
+  #onPause
+  #onResume
+  #onAbort
+  #paused = false
+
+  constructor (onPause, onResume, onAbort) {
+    this.#onPause = onPause
+    this.#onResume = onResume
+    this.#onAbort = onAbort
+    this.target = null
+  }
+
+  pause () {
+    if (this.#paused) {
+      return
+    }
+
+    this.#paused = true
+    this.#onPause()
+  }
+
+  resume () {
+    if (!this.#paused) {
+      return
+    }
+
+    this.#paused = false
+    this.#onResume()
+  }
+
+  abort (reason) {
+    this.target?.abort(reason)
+    this.#onAbort(reason)
+  }
+
+  get paused () { return this.#paused }
+  get aborted () { return this.target?.aborted ?? false }
+  get reason () { return this.target?.reason ?? null }
+  get rawHeaders () { return this.target?.rawHeaders ?? null }
+  set rawHeaders (value) {
+    if (this.target) {
+      this.target.rawHeaders = value
+    }
+  }
+
+  get rawTrailers () { return this.target?.rawTrailers ?? null }
+  set rawTrailers (value) {
+    if (this.target) {
+      this.target.rawTrailers = value
+    }
+  }
+}
+
 /** @type {Record<string, () => DecompressorStream>} */
 const supportedEncodings = {
   gzip: createGunzip,
@@ -45552,6 +45835,31 @@ const supportedEncodings = {
 }
 
 const defaultSkipStatusCodes = /** @type {const} */ ([204, 304])
+const defaultMaxSize = 0
+
+/**
+ * Limits the output of one stage in a decompression chain.
+ * @param {number} maxSize - Maximum output size in bytes
+ * @returns {Transform}
+ */
+function createMaxSizeLimiter (maxSize) {
+  let size = 0
+
+  return new TransformStream({
+    transform (chunk, _encoding, callback) {
+      const decompressedSize = size + chunk.length
+      if (decompressedSize > maxSize) {
+        callback(new ResponseExceededMaxSizeError(
+          `Decompressed response size (${decompressedSize}) exceeded maxSize (${maxSize})`
+        ))
+        return
+      }
+
+      size = decompressedSize
+      callback(null, chunk)
+    }
+  })
+}
 
 let warningEmitted = /** @type {boolean} */ (false)
 
@@ -45559,20 +45867,150 @@ let warningEmitted = /** @type {boolean} */ (false)
  * @typedef {Object} DecompressHandlerOptions
  * @property {number[]|Readonly<number[]>} [skipStatusCodes=[204, 304]] - List of status codes to skip decompression for
  * @property {boolean} [skipErrorResponses] - Whether to skip decompression for error responses (status codes >= 400)
+ * @property {number} [maxSize=0] - Maximum decompressed response size in bytes. 0 disables the limit
  */
 
 class DecompressHandler extends DecoratorHandler {
   /** @type {Transform[]} */
   #decompressors = []
+  /** @type {Record<string, string | string[]> | undefined} */
+  #trailers
   /** @type {Readonly<number[]>} */
   #skipStatusCodes
   /** @type {boolean} */
   #skipErrorResponses
+  /** @type {number} */
+  #maxSize
+  /** @type {number} */
+  #decompressedSize = 0
+  /** @type {boolean} */
+  #terminated = false
+  /** @type {boolean} */
+  #inputEnded = false
+  /** @type {boolean} */
+  #inputBackpressured = false
+  /** @type {boolean} */
+  #upstreamPaused = false
+  /** @type {boolean} */
+  #draining = false
+  /** @type {boolean} */
+  #drainRequested = false
+  /** @type {boolean} */
+  #completionPending = false
+  /** @type {DecompressorStream | undefined} */
+  #finalDecompressor
+  /** @type {DecompressController} */
+  #controller
+
+  constructor (handler, { skipStatusCodes = defaultSkipStatusCodes, skipErrorResponses = true, maxSize = defaultMaxSize } = {}) {
+    if (!Number.isSafeInteger(maxSize) || maxSize < 0) {
+      throw new InvalidArgumentError('maxSize must be a non-negative integer')
+    }
 
-  constructor (handler, { skipStatusCodes = defaultSkipStatusCodes, skipErrorResponses = true } = {}) {
     super(handler)
     this.#skipStatusCodes = skipStatusCodes
     this.#skipErrorResponses = skipErrorResponses
+    this.#maxSize = maxSize
+    this.#controller = new DecompressController(
+      () => this.#onDownstreamPause(),
+      () => this.#onDownstreamResume(),
+      reason => {
+        if (this.#inputEnded && !this.#terminated) {
+          this.onResponseError(this.#controller, reason)
+        }
+      }
+    )
+  }
+
+  #onDownstreamPause () {
+    this.#pauseUpstream()
+  }
+
+  #onDownstreamResume () {
+    const drainWasDeferred = this.#draining
+    this.#drainOutput()
+    if (!drainWasDeferred) {
+      this.#resumeUpstreamIfNeeded()
+      this.#finishIfReady()
+    }
+  }
+
+  #pauseUpstream () {
+    if (!this.#upstreamPaused && !this.#terminated) {
+      this.#upstreamPaused = true
+      this.#controller.target?.pause()
+    }
+  }
+
+  #resumeUpstreamIfNeeded () {
+    if (this.#upstreamPaused && !this.#controller.paused && !this.#inputBackpressured) {
+      this.#upstreamPaused = false
+      if (!this.#inputEnded) {
+        this.#controller.target?.resume()
+      }
+    }
+  }
+
+  #drainOutput () {
+    if (this.#terminated || this.#controller.paused || !this.#finalDecompressor) {
+      return
+    }
+
+    if (this.#draining) {
+      this.#drainRequested = true
+      return
+    }
+
+    this.#draining = true
+    try {
+      do {
+        this.#drainRequested = false
+        let chunk
+        while (!this.#terminated && !this.#controller.paused && (chunk = this.#finalDecompressor.read()) !== null) {
+          if (this.#maxSize > 0) {
+            const decompressedSize = this.#decompressedSize + chunk.length
+            if (decompressedSize > this.#maxSize) {
+              this.#fail(new ResponseExceededMaxSizeError(
+                `Decompressed response size (${decompressedSize}) exceeded maxSize (${this.#maxSize})`
+              ))
+              return
+            }
+
+            this.#decompressedSize = decompressedSize
+          }
+
+          const result = super.onResponseData(this.#controller, chunk)
+          if (result === false && !this.#controller.paused) {
+            this.#controller.pause()
+          }
+        }
+      } while (this.#drainRequested && !this.#terminated && !this.#controller.paused)
+    } finally {
+      this.#draining = false
+    }
+
+    this.#resumeUpstreamIfNeeded()
+    this.#finishIfReady()
+  }
+
+  #finishIfReady () {
+    if (this.#terminated || !this.#completionPending || this.#controller.paused || this.#draining) {
+      return
+    }
+
+    this.#terminated = true
+    this.#cleanupDecompressors()
+    super.onResponseEnd(this.#controller, this.#trailers)
+  }
+
+  #onDecompressionEnd () {
+    if (this.#terminated) {
+      return
+    }
+
+    this.#completionPending = true
+    this.#drainOutput()
+    this.#finishIfReady()
   }
 
   /**
@@ -45592,7 +46030,7 @@ class DecompressHandler extends DecoratorHandler {
    * Creates a chain of decompressors for multiple content encodings
    *
    * @param {string} encodings - Comma-separated list of content encodings
-   * @returns {Array<DecompressorStream>} - Array of decompressor streams
+   * @returns {Array<Transform>} - Array of decompressor and limiting streams
    * @throws {Error} - If the number of content-encodings exceeds the maximum allowed
    */
   #createDecompressionChain (encodings) {
@@ -45620,60 +46058,97 @@ class DecompressHandler extends DecoratorHandler {
       decompressors.push(supportedEncodings[encoding]())
     }
 
-    return decompressors
+    if (decompressors.length < 2) {
+      return decompressors
+    }
+
+    /** @type {Transform[]} */
+    const streams = []
+    for (let i = 0; i < decompressors.length; i++) {
+      streams.push(decompressors[i])
+      if (i < decompressors.length - 1 && this.#maxSize > 0) {
+        streams.push(createMaxSizeLimiter(this.#maxSize))
+      }
+    }
+
+    return streams
   }
 
   /**
-   * Sets up event handlers for a decompressor stream using readable events
-   * @param {DecompressorStream} decompressor - The decompressor stream
-   * @param {Controller} controller - The controller to coordinate with
+   * Stops decompression and reports an error.
+   * @param {Error} error - The decompression error
    * @returns {void}
    */
-  #setupDecompressorEvents (decompressor, controller) {
-    decompressor.on('readable', () => {
-      let chunk
-      while ((chunk = decompressor.read()) !== null) {
-        const result = super.onResponseData(controller, chunk)
-        if (result === false) {
-          break
-        }
-      }
-    })
+  #fail (error) {
+    if (this.#terminated) {
+      return
+    }
 
-    decompressor.on('error', (error) => {
-      super.onResponseError(controller, error)
-    })
+    if (this.#inputEnded) {
+      // The request is already marked complete once the compressed input ends,
+      // so controller.abort() can no longer propagate decoder flush errors.
+      this.onResponseError(this.#controller, error)
+    } else {
+      this.#controller.abort(error)
+    }
+  }
+
+  /**
+   * Sets up event handlers for the final decompressor stream.
+   * @param {DecompressorStream} decompressor - The decompressor stream
+   * @returns {void}
+   */
+  #setupDecompressorEvents (decompressor) {
+    this.#finalDecompressor = decompressor
+    decompressor.on('readable', () => this.#drainOutput())
+    decompressor.on('error', (error) => this.#fail(error))
   }
 
   /**
    * Sets up event handling for a single decompressor
-   * @param {Controller} controller - The controller to handle events
    * @returns {void}
    */
-  #setupSingleDecompressor (controller) {
+  #setupSingleDecompressor () {
     const decompressor = this.#decompressors[0]
-    this.#setupDecompressorEvents(decompressor, controller)
+    this.#setupDecompressorEvents(decompressor)
 
-    decompressor.on('end', () => {
-      super.onResponseEnd(controller, {})
-    })
+    decompressor.on('end', () => this.#onDecompressionEnd())
   }
 
   /**
    * Sets up event handling for multiple chained decompressors using pipeline
-   * @param {Controller} controller - The controller to handle events
    * @returns {void}
    */
-  #setupMultipleDecompressors (controller) {
+  #setupMultipleDecompressors () {
     const lastDecompressor = this.#decompressors[this.#decompressors.length - 1]
-    this.#setupDecompressorEvents(lastDecompressor, controller)
+    this.#setupDecompressorEvents(lastDecompressor)
 
     pipeline(this.#decompressors, (err) => {
-      if (err) {
-        super.onResponseError(controller, err)
+      if (this.#terminated) {
         return
       }
-      super.onResponseEnd(controller, {})
+
+      if (err) {
+        this.#fail(err)
+        return
+      }
+
+      this.#onDecompressionEnd()
+    })
+  }
+
+  #setupInputBackpressure () {
+    const decompressor = this.#decompressors[0]
+    decompressor.on('drain', () => {
+      if (this.#terminated) {
+        return
+      }
+
+      this.#inputBackpressured = false
+      if (!this.#controller.paused) {
+        this.#drainOutput()
+        this.#resumeUpstreamIfNeeded()
+      }
     })
   }
 
@@ -45683,6 +46158,16 @@ class DecompressHandler extends DecoratorHandler {
    */
   #cleanupDecompressors () {
     this.#decompressors.length = 0
+    this.#finalDecompressor = undefined
+  }
+
+  onRequestStart (controller, context) {
+    this.#controller.target = controller
+    return super.onRequestStart(this.#controller, context)
+  }
+
+  onRequestUpgrade (controller, statusCode, headers, socket) {
+    return super.onRequestUpgrade(this.#controller, statusCode, headers, socket)
   }
 
   /**
@@ -45697,14 +46182,14 @@ class DecompressHandler extends DecoratorHandler {
 
     // If content encoding is not supported or status code is in skip list
     if (this.#shouldSkipDecompression(contentEncoding, statusCode)) {
-      return super.onResponseStart(controller, statusCode, headers, statusMessage)
+      return super.onResponseStart(this.#controller, statusCode, headers, statusMessage)
     }
 
     const decompressors = this.#createDecompressionChain(contentEncoding.toLowerCase())
 
     if (decompressors.length === 0) {
       this.#cleanupDecompressors()
-      return super.onResponseStart(controller, statusCode, headers, statusMessage)
+      return super.onResponseStart(this.#controller, statusCode, headers, statusMessage)
     }
 
     this.#decompressors = decompressors
@@ -45712,13 +46197,41 @@ class DecompressHandler extends DecoratorHandler {
     // Remove compression headers since we're decompressing
     const { 'content-encoding': _, 'content-length': __, ...newHeaders } = headers
 
-    if (this.#decompressors.length === 1) {
-      this.#setupSingleDecompressor(controller)
-    } else {
-      this.#setupMultipleDecompressors(controller)
+    if (this.#controller.rawHeaders) {
+      const rawHeaders = this.#controller.rawHeaders
+
+      if (Array.isArray(rawHeaders)) {
+        const filteredHeaders = []
+        for (let i = 0; i < rawHeaders.length; i += 2) {
+          const headerName = rawHeaders[i]
+          const name = Buffer.isBuffer(headerName) ? headerName.toString('latin1') : `${headerName}`
+          const lowerName = name.toLowerCase()
+
+          if (lowerName === 'content-encoding' || lowerName === 'content-length') {
+            continue
+          }
+
+          filteredHeaders.push(rawHeaders[i], rawHeaders[i + 1])
+        }
+        rawHeaders.splice(0, rawHeaders.length, ...filteredHeaders)
+      } else if (typeof rawHeaders === 'object') {
+        for (const name of Object.keys(rawHeaders)) {
+          const lowerName = name.toLowerCase()
+          if (lowerName === 'content-encoding' || lowerName === 'content-length') {
+            delete rawHeaders[name]
+          }
+        }
+      }
     }
 
-    return super.onResponseStart(controller, statusCode, newHeaders, statusMessage)
+    this.#setupInputBackpressure()
+    if (this.#decompressors.length === 1) {
+      this.#setupSingleDecompressor()
+    } else {
+      this.#setupMultipleDecompressors()
+    }
+
+    return super.onResponseStart(this.#controller, statusCode, newHeaders, statusMessage)
   }
 
   /**
@@ -45728,10 +46241,13 @@ class DecompressHandler extends DecoratorHandler {
    */
   onResponseData (controller, chunk) {
     if (this.#decompressors.length > 0) {
-      this.#decompressors[0].write(chunk)
+      if (!this.#decompressors[0].write(chunk)) {
+        this.#inputBackpressured = true
+        this.#pauseUpstream()
+      }
       return
     }
-    super.onResponseData(controller, chunk)
+    return super.onResponseData(this.#controller, chunk)
   }
 
   /**
@@ -45741,11 +46257,12 @@ class DecompressHandler extends DecoratorHandler {
    */
   onResponseEnd (controller, trailers) {
     if (this.#decompressors.length > 0) {
+      this.#inputEnded = true
+      this.#trailers = trailers
       this.#decompressors[0].end()
-      this.#cleanupDecompressors()
       return
     }
-    super.onResponseEnd(controller, trailers)
+    return super.onResponseEnd(this.#controller, trailers)
   }
 
   /**
@@ -45754,13 +46271,16 @@ class DecompressHandler extends DecoratorHandler {
    * @returns {void}
    */
   onResponseError (controller, err) {
-    if (this.#decompressors.length > 0) {
-      for (const decompressor of this.#decompressors) {
-        decompressor.destroy(err)
-      }
-      this.#cleanupDecompressors()
+    if (this.#terminated) {
+      return
     }
-    super.onResponseError(controller, err)
+
+    this.#terminated = true
+    for (const decompressor of this.#decompressors) {
+      decompressor.destroy()
+    }
+    this.#cleanupDecompressors()
+    super.onResponseError(this.#controller, err)
   }
 }
 
@@ -46509,7 +47029,6 @@ class DumpHandler extends DecoratorHandler {
   #maxSize = 1024 * 1024
   #dumped = false
   #size = 0
-  #controller = null
   aborted = false
   reason = false
 
@@ -46531,7 +47050,6 @@ class DumpHandler extends DecoratorHandler {
 
   onRequestStart (controller, context) {
     controller.abort = this.#abort.bind(this)
-    this.#controller = controller
 
     return super.onRequestStart(controller, context)
   }
@@ -46555,43 +47073,32 @@ class DumpHandler extends DecoratorHandler {
   }
 
   onResponseError (controller, err) {
-    if (this.#dumped) {
-      return
-    }
-
-    // On network errors before connect, controller will be null
-    err = this.#controller?.reason ?? err
-
-    super.onResponseError(controller, err)
+    super.onResponseError(controller, this.aborted === true ? this.reason : err)
   }
 
   onResponseData (controller, chunk) {
     this.#size = this.#size + chunk.length
 
-    if (this.#size >= this.#maxSize) {
-      this.#dumped = true
+    if (this.#size > this.#maxSize) {
+      throw new RequestAbortedError(
+        `Response size (${this.#size}) larger than maxSize (${this.#maxSize})`
+      )
+    }
 
-      if (this.aborted === true) {
-        super.onResponseError(controller, this.reason)
-      } else {
-        super.onResponseEnd(controller, {})
-      }
+    if (this.#size === this.#maxSize) {
+      this.#dumped = true
     }
 
     return true
   }
 
   onResponseEnd (controller, trailers) {
-    if (this.#dumped) {
-      return
-    }
-
-    if (this.#controller.aborted === true) {
+    if (this.aborted === true) {
       super.onResponseError(controller, this.reason)
       return
     }
 
-    super.onResponseEnd(controller, trailers)
+    super.onResponseEnd(controller, this.#dumped ? {} : trailers)
   }
 }
 
@@ -54018,6 +54525,49 @@ const COLON = 0x3A
  */
 const SPACE = 0x20
 
+const DATA = Buffer.from('data')
+const EVENT = Buffer.from('event')
+const ID = Buffer.from('id')
+const RETRY = Buffer.from('retry')
+
+function isASCIINumberBytes (buffer, start) {
+  if (start >= buffer.length) {
+    return false
+  }
+
+  for (let i = start; i < buffer.length; i++) {
+    if (buffer[i] < 0x30 || buffer[i] > 0x39) {
+      return false
+    }
+  }
+
+  return true
+}
+
+function isValidLastEventIdBytes (buffer, start) {
+  for (let i = start; i < buffer.length; i++) {
+    if (buffer[i] === 0x00) {
+      return false
+    }
+  }
+
+  return true
+}
+
+function isFieldName (line, length, field) {
+  if (length !== field.length) {
+    return false
+  }
+
+  for (let i = 0; i < length; i++) {
+    if (line[i] !== field[i]) {
+      return false
+    }
+  }
+
+  return true
+}
+
 /**
  * @typedef {object} EventSourceStreamEvent
  * @type {object}
@@ -54058,11 +54608,14 @@ class EventSourceStream extends Transform {
   eventEndCheck = false
 
   /**
-   * @type {Buffer|null}
+   * @type {Buffer[]}
    */
-  buffer = null
+  chunks = []
 
+  chunkIndex = 0
   pos = 0
+  lineChunkIndex = 0
+  linePos = 0
 
   event = {
     data: undefined,
@@ -54102,92 +54655,20 @@ class EventSourceStream extends Transform {
       return
     }
 
-    // Cache the chunk in the buffer, as the data might not be complete while
-    // processing it
-    // TODO: Investigate if there is a more performant way to handle
-    // incoming chunks
-    // see: https://github.com/nodejs/undici/issues/2630
-    if (this.buffer) {
-      this.buffer = Buffer.concat([this.buffer, chunk])
-    } else {
-      this.buffer = chunk
-    }
+    this.chunks.push(chunk)
 
     // Strip leading byte-order-mark if we opened the stream and started
     // the processing of the incoming data
     if (this.checkBOM) {
-      switch (this.buffer.length) {
-        case 1:
-          // Check if the first byte is the same as the first byte of the BOM
-          if (this.buffer[0] === BOM[0]) {
-            // If it is, we need to wait for more data
-            callback()
-            return
-          }
-          // Set the checkBOM flag to false as we don't need to check for the
-          // BOM anymore
-          this.checkBOM = false
-
-          // The buffer only contains one byte so we need to wait for more data
-          callback()
-          return
-        case 2:
-          // Check if the first two bytes are the same as the first two bytes
-          // of the BOM
-          if (
-            this.buffer[0] === BOM[0] &&
-            this.buffer[1] === BOM[1]
-          ) {
-            // If it is, we need to wait for more data, because the third byte
-            // is needed to determine if it is the BOM or not
-            callback()
-            return
-          }
-
-          // Set the checkBOM flag to false as we don't need to check for the
-          // BOM anymore
-          this.checkBOM = false
-          break
-        case 3:
-          // Check if the first three bytes are the same as the first three
-          // bytes of the BOM
-          if (
-            this.buffer[0] === BOM[0] &&
-            this.buffer[1] === BOM[1] &&
-            this.buffer[2] === BOM[2]
-          ) {
-            // If it is, we can drop the buffered data, as it is only the BOM
-            this.buffer = Buffer.alloc(0)
-            // Set the checkBOM flag to false as we don't need to check for the
-            // BOM anymore
-            this.checkBOM = false
-
-            // Await more data
-            callback()
-            return
-          }
-          // If it is not the BOM, we can start processing the data
-          this.checkBOM = false
-          break
-        default:
-          // The buffer is longer than 3 bytes, so we can drop the BOM if it is
-          // present
-          if (
-            this.buffer[0] === BOM[0] &&
-            this.buffer[1] === BOM[1] &&
-            this.buffer[2] === BOM[2]
-          ) {
-            // Remove the BOM from the buffer
-            this.buffer = this.buffer.subarray(3)
-          }
-
-          // Set the checkBOM flag to false as we don't need to check for the
-          this.checkBOM = false
-          break
+      if (this.handleBOM()) {
+        callback()
+        return
       }
     }
 
-    while (this.pos < this.buffer.length) {
+    while (this.hasCurrentByte()) {
+      const byte = this.currentByte()
+
       // If the previous line ended with an end-of-line, we need to check
       // if the next character is also an end-of-line.
       if (this.eventEndCheck) {
@@ -54200,10 +54681,9 @@ class EventSourceStream extends Transform {
         if (this.crlfCheck) {
           // If the current character is a line feed, we can remove it
           // from the buffer and reset the crlfCheck flag
-          if (this.buffer[this.pos] === LF) {
-            this.buffer = this.buffer.subarray(this.pos + 1)
-            this.pos = 0
+          if (byte === LF) {
             this.crlfCheck = false
+            this.consumeCurrentByte()
 
             // It is possible that the line feed is not the end of the
             // event. We need to check if the next character is an
@@ -54219,19 +54699,17 @@ class EventSourceStream extends Transform {
           this.crlfCheck = false
         }
 
-        if (this.buffer[this.pos] === LF || this.buffer[this.pos] === CR) {
+        if (byte === LF || byte === CR) {
           // If the current character is a carriage return, we need to
           // set the crlfCheck flag to true, as we need to check if the
           // next character is a line feed so we can remove it from the
           // buffer
-          if (this.buffer[this.pos] === CR) {
+          if (byte === CR) {
             this.crlfCheck = true
           }
 
-          this.buffer = this.buffer.subarray(this.pos + 1)
-          this.pos = 0
-          if (
-            this.event.data !== undefined || this.event.event || this.event.id !== undefined || this.event.retry) {
+          this.consumeCurrentByte()
+          if (this.hasPendingEvent()) {
             this.processEvent(this.event)
           }
           this.clearEvent()
@@ -54245,22 +54723,18 @@ class EventSourceStream extends Transform {
 
       // If the current character is an end-of-line, we can process the
       // line
-      if (this.buffer[this.pos] === LF || this.buffer[this.pos] === CR) {
+      if (byte === LF || byte === CR) {
         // If the current character is a carriage return, we need to
         // set the crlfCheck flag to true, as we need to check if the
         // next character is a line feed
-        if (this.buffer[this.pos] === CR) {
+        if (byte === CR) {
           this.crlfCheck = true
         }
 
         // In any case, we can process the line as we reached an
         // end-of-line character
-        this.parseLine(this.buffer.subarray(0, this.pos), this.event)
-
-        // Remove the processed line from the buffer
-        this.buffer = this.buffer.subarray(this.pos + 1)
-        // Reset the position as we removed the processed line from the buffer
-        this.pos = 0
+        this.parseLine(this.readLine(), this.event)
+        this.consumeCurrentByte()
         // A line was processed and this could be the end of the event. We need
         // to check if the next line is empty to determine if the event is
         // finished.
@@ -54268,7 +54742,7 @@ class EventSourceStream extends Transform {
         continue
       }
 
-      this.pos++
+      this.advanceCursor()
     }
 
     callback()
@@ -54293,64 +54767,53 @@ class EventSourceStream extends Transform {
       return
     }
 
-    let field = ''
-    let value = ''
+    let fieldLength = line.length
+    let valueStart = line.length
 
     // If the line contains a U+003A COLON character (:)
     if (colonPosition !== -1) {
-      // Collect the characters on the line before the first U+003A COLON
-      // character (:), and let field be that string.
-      // TODO: Investigate if there is a more performant way to extract the
-      // field
-      // see: https://github.com/nodejs/undici/issues/2630
-      field = line.subarray(0, colonPosition).toString('utf8')
+      fieldLength = colonPosition
 
       // Collect the characters on the line after the first U+003A COLON
       // character (:), and let value be that string.
       // If value starts with a U+0020 SPACE character, remove it from value.
-      let valueStart = colonPosition + 1
+      valueStart = colonPosition + 1
       if (line[valueStart] === SPACE) {
         ++valueStart
       }
-      // TODO: Investigate if there is a more performant way to extract the
-      // value
-      // see: https://github.com/nodejs/undici/issues/2630
-      value = line.subarray(valueStart).toString('utf8')
-
-      // Otherwise, the string is not empty but does not contain a U+003A COLON
-      // character (:)
-    } else {
-      // Process the field using the steps described below, using the whole
-      // line as the field name, and the empty string as the field value.
-      field = line.toString('utf8')
-      value = ''
     }
 
-    // Modify the event with the field name and value. The value is also
-    // decoded as UTF-8
-    switch (field) {
-      case 'data':
-        if (event[field] === undefined) {
-          event[field] = value
-        } else {
-          event[field] += `\n${value}`
-        }
-        break
-      case 'retry':
-        if (isASCIINumber(value)) {
-          event[field] = value
-        }
-        break
-      case 'id':
-        if (isValidLastEventId(value)) {
-          event[field] = value
-        }
-        break
-      case 'event':
-        if (value.length > 0) {
-          event[field] = value
-        }
-        break
+    if (isFieldName(line, fieldLength, DATA)) {
+      const value = line.toString('utf8', valueStart)
+
+      if (event.data === undefined) {
+        event.data = value
+      } else {
+        event.data += `\n${value}`
+      }
+      return
+    }
+
+    if (isFieldName(line, fieldLength, RETRY)) {
+      if (isASCIINumberBytes(line, valueStart)) {
+        event.retry = line.toString('utf8', valueStart)
+      }
+      return
+    }
+
+    if (isFieldName(line, fieldLength, ID)) {
+      if (isValidLastEventIdBytes(line, valueStart)) {
+        event.id = line.toString('utf8', valueStart)
+      }
+      return
+    }
+
+    if (isFieldName(line, fieldLength, EVENT)) {
+      const value = line.toString('utf8', valueStart)
+
+      if (value.length > 0) {
+        event.event = value
+      }
     }
   }
 
@@ -54380,13 +54843,152 @@ class EventSourceStream extends Transform {
   }
 
   clearEvent () {
-    this.event = {
-      data: undefined,
-      event: undefined,
-      id: undefined,
-      retry: undefined
+    this.event.data = undefined
+    this.event.event = undefined
+    this.event.id = undefined
+    this.event.retry = undefined
+  }
+
+  hasPendingEvent () {
+    return this.event.data !== undefined ||
+      this.event.event !== undefined ||
+      this.event.id !== undefined ||
+      this.event.retry !== undefined
+  }
+
+  hasCurrentByte () {
+    return this.chunkIndex < this.chunks.length &&
+      this.pos < this.chunks[this.chunkIndex].length
+  }
+
+  currentByte () {
+    return this.chunks[this.chunkIndex][this.pos]
+  }
+
+  consumeCurrentByte () {
+    this.advanceCursor()
+    this.syncLineStartToCursor()
+  }
+
+  advanceCursor () {
+    this.pos++
+
+    while (this.chunkIndex < this.chunks.length && this.pos >= this.chunks[this.chunkIndex].length) {
+      this.chunkIndex++
+      this.pos = 0
     }
   }
+
+  syncLineStartToCursor () {
+    this.lineChunkIndex = this.chunkIndex
+    this.linePos = this.pos
+    this.dropConsumedChunks()
+  }
+
+  dropConsumedChunks () {
+    while (this.lineChunkIndex > 0) {
+      this.chunks.shift()
+      this.lineChunkIndex--
+      this.chunkIndex--
+    }
+
+    if (this.chunkIndex === this.chunks.length) {
+      this.chunks.length = 0
+      this.chunkIndex = 0
+      this.pos = 0
+      this.lineChunkIndex = 0
+      this.linePos = 0
+    }
+  }
+
+  readLine () {
+    if (this.lineChunkIndex === this.chunkIndex) {
+      return this.chunks[this.chunkIndex].subarray(this.linePos, this.pos)
+    }
+
+    const chunks = []
+    let length = 0
+
+    for (let i = this.lineChunkIndex; i <= this.chunkIndex; i++) {
+      const chunk = this.chunks[i]
+      const start = i === this.lineChunkIndex ? this.linePos : 0
+      const end = i === this.chunkIndex ? this.pos : chunk.length
+      const slice = chunk.subarray(start, end)
+      length += slice.length
+      chunks.push(slice)
+    }
+
+    return Buffer.concat(chunks, length)
+  }
+
+  peekBufferedByte (offset) {
+    let chunkIndex = this.lineChunkIndex
+    let pos = this.linePos
+
+    while (chunkIndex < this.chunks.length) {
+      const chunk = this.chunks[chunkIndex]
+      const remaining = chunk.length - pos
+
+      if (offset < remaining) {
+        return chunk[pos + offset]
+      }
+
+      offset -= remaining
+      chunkIndex++
+      pos = 0
+    }
+  }
+
+  discardLeadingBytes (count) {
+    while (count > 0 && this.lineChunkIndex < this.chunks.length) {
+      const chunk = this.chunks[this.lineChunkIndex]
+      const remaining = chunk.length - this.linePos
+
+      if (count < remaining) {
+        this.linePos += count
+        count = 0
+      } else {
+        count -= remaining
+        this.lineChunkIndex++
+        this.linePos = 0
+      }
+    }
+
+    this.chunkIndex = this.lineChunkIndex
+    this.pos = this.linePos
+    this.dropConsumedChunks()
+  }
+
+  handleBOM () {
+    const first = this.peekBufferedByte(0)
+    const second = this.peekBufferedByte(1)
+    const third = this.peekBufferedByte(2)
+
+    if (second === undefined) {
+      if (first === BOM[0]) {
+        return true
+      }
+
+      this.checkBOM = false
+      return true
+    }
+
+    if (third === undefined) {
+      if (first === BOM[0] && second === BOM[1]) {
+        return true
+      }
+
+      this.checkBOM = false
+      return false
+    }
+
+    if (first === BOM[0] && second === BOM[1] && third === BOM[2]) {
+      this.discardLeadingBytes(3)
+    }
+
+    this.checkBOM = false
+    return !this.hasCurrentByte()
+  }
 }
 
 module.exports = {
@@ -65234,13 +65836,13 @@ function establishWebSocketConnection (url, protocols, client, handler, options)
         // The presence of a session property on the socket indicates HTTP2
         // HTTP1
         if (response.socket?.session == null) {
-          failWebsocketConnection(handler, 1002, 'Received network error or non-101 status code.', response.error)
+          failHandshake(handler, response, 1002, 'Received network error or non-101 status code.', response.error)
           return
         }
 
         // HTTP2
         if (response.status !== 200) {
-          failWebsocketConnection(handler, 1002, 'Received network error or non-200 status code.', response.error)
+          failHandshake(handler, response, 1002, 'Received network error or non-200 status code.', response.error)
           return
         }
       }
@@ -65255,7 +65857,7 @@ function establishWebSocketConnection (url, protocols, client, handler, options)
       //    header list results in null, failure, or the empty byte
       //    sequence, then fail the WebSocket connection.
       if (protocols.length !== 0 && !response.headersList.get('Sec-WebSocket-Protocol')) {
-        failWebsocketConnection(handler, 1002, 'Server did not respond with sent protocols.')
+        failHandshake(handler, response, 1002, 'Server did not respond with sent protocols.')
         return
       }
 
@@ -65271,7 +65873,7 @@ function establishWebSocketConnection (url, protocols, client, handler, options)
       //    _Fail the WebSocket Connection_.
       //    For H2, no upgrade header is expected.
       if (response.socket.session == null && response.headersList.get('Upgrade')?.toLowerCase() !== 'websocket') {
-        failWebsocketConnection(handler, 1002, 'Server did not set Upgrade header to "websocket".')
+        failHandshake(handler, response, 1002, 'Server did not set Upgrade header to "websocket".')
         return
       }
 
@@ -65281,7 +65883,7 @@ function establishWebSocketConnection (url, protocols, client, handler, options)
       //    MUST _Fail the WebSocket Connection_.
       //    For H2, no connection header is expected.
       if (response.socket.session == null && response.headersList.get('Connection')?.toLowerCase() !== 'upgrade') {
-        failWebsocketConnection(handler, 1002, 'Server did not set Connection header to "upgrade".')
+        failHandshake(handler, response, 1002, 'Server did not set Connection header to "upgrade".')
         return
       }
 
@@ -65295,7 +65897,7 @@ function establishWebSocketConnection (url, protocols, client, handler, options)
       const secWSAccept = response.headersList.get('Sec-WebSocket-Accept')
       const digest = crypto.hash('sha1', keyValue + uid, 'base64')
       if (secWSAccept !== digest) {
-        failWebsocketConnection(handler, 1002, 'Incorrect hash received in Sec-WebSocket-Accept header.')
+        failHandshake(handler, response, 1002, 'Incorrect hash received in Sec-WebSocket-Accept header.')
         return
       }
 
@@ -65313,7 +65915,7 @@ function establishWebSocketConnection (url, protocols, client, handler, options)
         extensions = parseExtensions(secExtension)
 
         if (!extensions.has('permessage-deflate')) {
-          failWebsocketConnection(handler, 1002, 'Sec-WebSocket-Extensions header does not match.')
+          failHandshake(handler, response, 1002, 'Sec-WebSocket-Extensions header does not match.')
           return
         }
       }
@@ -65333,8 +65935,8 @@ function establishWebSocketConnection (url, protocols, client, handler, options)
         // is specified, the server needs to include the same field and one of
         // the selected subprotocol values in its response for the connection to
         // be established.
-        if (!requestProtocols.includes(secProtocol)) {
-          failWebsocketConnection(handler, 1002, 'Protocol was not set in the opening handshake.')
+        if (requestProtocols === null || !requestProtocols.includes(secProtocol)) {
+          failHandshake(handler, response, 1002, 'Protocol was not set in the opening handshake.')
           return
         }
       }
@@ -65429,6 +66031,16 @@ function closeWebSocketConnection (object, code, reason, validate = false) {
   }
 }
 
+function failHandshake (handler, response, code, reason, cause) {
+  // The H2 upgrade request has already completed and handed off its stream.
+  // Aborting the request cannot close that stream after handshake validation fails.
+  if (response.socket?.session != null && !response.socket.destroyed) {
+    response.socket.destroy()
+  }
+
+  failWebsocketConnection(handler, code, reason, cause)
+}
+
 /**
  * @param {import('./websocket').Handler} handler
  * @param {number} code
@@ -66147,7 +66759,12 @@ class PerMessageDeflate {
 
         if (this.#maxPayloadSize > 0 && this.#inflate[kLength] > this.#maxPayloadSize) {
           callback(new MessageSizeExceededError())
+          // The inflater may still hold buffered input that can emit a late
+          // zlib error. Remove the data listener, then deterministically stop
+          // the stream so a subsequent 'error' cannot fire without a listener
+          // (which would terminate the process as an unhandled error event).
           this.#inflate.removeAllListeners()
+          this.#inflate.destroy()
           this.#inflate = null
           return
         }
@@ -66970,9 +67587,9 @@ class WebSocketStream {
   /** @type {ReadableStreamDefaultController} */
   #readableStreamController
 
-  // Each WebSocketStream object has an associated writable stream , which is a WritableStream .
-  /** @type {WritableStream} */
-  #writableStream
+  // Retain the controller so the writable stream can be errored while locked.
+  /** @type {WritableStreamDefaultController} */
+  #writableStreamController
 
   // Each WebSocketStream object has an associated boolean handshake aborted , which is initially false.
   #handshakeAborted = false
@@ -67236,6 +67853,9 @@ class WebSocketStream {
     // 12. Let writable be a new WritableStream .
     // 13. Set up writable with writeAlgorithm , closeAlgorithm , and abortAlgorithm .
     const writable = new WritableStream({
+      start: (controller) => {
+        this.#writableStreamController = controller
+      },
       write: (chunk) => this.#write(chunk),
       close: () => closeWebSocketConnection(this.#handler, null, null),
       abort: (reason) => this.#closeUsingReason(reason)
@@ -67244,9 +67864,6 @@ class WebSocketStream {
     // Set stream ’s readable stream to readable .
     this.#readableStream = readable
 
-    // Set stream ’s writable stream to writable .
-    this.#writableStream = writable
-
     // Resolve stream ’s opened promise with WebSocketOpenInfo «[ " extensions " → extensions , " protocol " → protocol , " readable " → readable , " writable " → writable ]».
     this.#openedPromise.resolve({
       extensions,
@@ -67332,9 +67949,7 @@ class WebSocketStream {
       this.#readableStreamController.close()
 
       // 6.2. Error stream ’s writable stream with an " InvalidStateError " DOMException indicating that a closed WebSocketStream cannot be written to.
-      if (!this.#writableStream.locked) {
-        this.#writableStream.abort(new DOMException('A closed WebSocketStream cannot be written to', 'InvalidStateError'))
-      }
+      this.#writableStreamController.error(new DOMException('A closed WebSocketStream cannot be written to', 'InvalidStateError'))
 
       // 6.3. Resolve stream ’s closed promise with WebSocketCloseInfo «[ " closeCode " → code , " reason " → reason ]».
       this.#closedPromise.resolve({
@@ -67351,7 +67966,7 @@ class WebSocketStream {
       this.#readableStreamController?.error(error)
 
       // 7.3. Error stream ’s writable stream with error .
-      this.#writableStream?.abort(error)
+      this.#writableStreamController?.error(error)
 
       // 7.4. Reject stream ’s closed promise with error .
       this.#closedPromise.reject(error)
diff --git a/dist/run/index.js b/dist/run/index.js
index b5a4ce4..6cd357d 100644
--- a/dist/run/index.js
+++ b/dist/run/index.js
@@ -34858,11 +34858,32 @@ class Request {
     }
   }
 
-  onUpgrade (statusCode, headers, socket) {
+  /**
+   * @param {number} statusCode
+   * @param {Buffer[]|string[]} headers
+   * @param {import('node:stream').Duplex} socket
+   * @param {string} [statusText]
+   */
+  onUpgrade (statusCode, headers, socket, statusText = '') {
+    this.onFinally()
+
     assert(!this.aborted)
     assert(!this.completed)
 
-    return this[kHandler].onUpgrade(statusCode, headers, socket)
+    if (channels.headers.hasSubscribers) {
+      channels.headers.publish({ request: this, response: { statusCode, headers, statusText } })
+    }
+
+    const result = this[kHandler].onUpgrade(statusCode, headers, socket)
+
+    if (!this.aborted) {
+      this.completed = true
+      if (channels.trailers.hasSubscribers) {
+        channels.trailers.publish({ request: this, trailers: [] })
+      }
+    }
+
+    return result
   }
 
   onComplete (trailers) {
@@ -37144,14 +37165,16 @@ function defaultFactory (origin, opts) {
 }
 
 class BalancedPool extends PoolBase {
-  constructor (upstreams = [], { factory = defaultFactory, ...opts } = {}) {
+  constructor (upstreams = [], { factory = defaultFactory, connect, tls, ...opts } = {}) {
     if (typeof factory !== 'function') {
       throw new InvalidArgumentError('factory must be a function.')
     }
 
     super(opts)
 
-    this[kOptions] = { ...util.deepClone(opts) }
+    if (connect && typeof connect !== 'function') connect = { ...connect }
+    if (tls && typeof tls !== 'function') tls = { ...tls }
+    this[kOptions] = { ...util.deepClone(opts), connect, tls }
     this[kOptions].interceptors = opts.interceptors
       ? { ...opts.interceptors }
       : undefined
@@ -37391,8 +37414,14 @@ function lazyllhttp () {
 
   let mod
 
-  // We disable wasm SIMD on ppc64 as it seems to be broken on Power 9 architectures.
-  let useWasmSIMD = process.arch !== 'ppc64'
+  // We disable wasm SIMD on older versions of Node.js on ppc64 that are broken on Power >=9 architectures.
+  let useWasmSIMD = true
+  if (process.arch === 'ppc64') {
+    const [major, minor] = process.versions.node.split('.').map(n => parseInt(n, 10))
+    if (major < 24 || (major === 24 && minor < 12)) {
+      useWasmSIMD = false
+    }
+  }
   // The Env Variable UNDICI_NO_WASM_SIMD allows explicitly overriding the default behavior
   if (process.env.UNDICI_NO_WASM_SIMD === '1') {
     useWasmSIMD = false
@@ -37843,7 +37872,7 @@ class Parser {
    * @param {Buffer} head
    */
   onUpgrade (head) {
-    const { upgrade, client, socket, headers, statusCode } = this
+    const { upgrade, client, socket, headers, statusCode, statusText } = this
 
     assert(upgrade)
     assert(client[kSocket] === socket)
@@ -37878,8 +37907,9 @@ class Parser {
     client.emit('disconnect', client[kUrl], [client], new InformationalError('upgrade'))
 
     try {
-      request.onUpgrade(statusCode, headers, socket)
+      request.onUpgrade(statusCode, headers, socket, statusText)
     } catch (err) {
+      util.errorRequest(client, request, err)
       util.destroy(socket, err)
     }
 
@@ -38334,7 +38364,7 @@ function onSocketClose () {
 
 function clearIdleSocketValidation (socket) {
   if (socket[kIdleSocketValidationTimeout]) {
-    clearTimeout(socket[kIdleSocketValidationTimeout])
+    clearImmediate(socket[kIdleSocketValidationTimeout])
     socket[kIdleSocketValidationTimeout] = null
   }
 
@@ -38343,15 +38373,23 @@ function clearIdleSocketValidation (socket) {
 
 function scheduleIdleSocketValidation (client, socket) {
   socket[kIdleSocketValidation] = 1
-  socket[kIdleSocketValidationTimeout] = setTimeout(() => {
+  // Yield to the check phase (after poll) so unsolicited bytes / FIN / RST
+  // already pending on this idle keep-alive socket are processed before the
+  // next request is written (GHSA-35p6-xmwp-9g52).
+  //
+  // setTimeout(0) pays Node's ~1ms timer floor on every sequential reuse
+  // (#5493). setImmediate avoids that, but an *unref'd* Immediate lets poll
+  // block for ~500ms when the event loop is otherwise idle (#5600 / #5606).
+  // A ref'd Immediate both keeps the pending request alive and makes poll
+  // return immediately — the hybrid those issues asked for.
+  socket[kIdleSocketValidationTimeout] = setImmediate(() => {
     socket[kIdleSocketValidationTimeout] = null
     socket[kIdleSocketValidation] = 2
 
     if (client[kSocket] === socket && !socket.destroyed) {
       client[kResume]()
     }
-  }, 0)
-  socket[kIdleSocketValidationTimeout].unref?.()
+  })
 }
 
 /**
@@ -39069,7 +39107,9 @@ const {
   RequestAbortedError,
   SocketError,
   InformationalError,
-  InvalidArgumentError
+  InvalidArgumentError,
+  HeadersTimeoutError,
+  BodyTimeoutError
 } = __nccwpck_require__(68707)
 const {
   kUrl,
@@ -39094,6 +39134,7 @@ const {
   kHTTPContext,
   kClosed,
   kBodyTimeout,
+  kHeadersTimeout,
   kEnableConnectProtocol,
   kRemoteSettings,
   kHTTP2Stream,
@@ -39280,7 +39321,11 @@ function resumeH2 (client) {
   const socket = client[kSocket]
 
   if (socket?.destroyed === false) {
-    if (client[kSize] === 0 || client[kMaxConcurrentStreams] === 0) {
+    // Only let the process exit when there is genuinely nothing outstanding.
+    // Unreffing because the peer advertised MAX_CONCURRENT_STREAMS = 0 left
+    // queued requests with nothing holding the event loop open, so the process
+    // could exit with status 0 while an awaited request never settled.
+    if (client[kSize] === 0) {
       socket.unref()
       client[kHTTP2Session].unref()
     } else {
@@ -39375,6 +39420,36 @@ function onHttp2SessionEnd () {
  * @this {import('http2').ClientHttp2Session}
  * @param {number} errorCode
  */
+// Backport of #5410 and #5569. HTTP/2 multiplexes, so requests complete out of
+// order; advancing kRunningIdx blindly retired whichever request happened to
+// sit at the head instead of the one that actually finished, which both lost
+// requests and left phantom running slots behind.
+function completeRequest (client, request, resetPendingIdx = false) {
+  const queue = client[kQueue]
+  const runningIdx = client[kRunningIdx]
+
+  // In-order completion: clear the request and advance without splicing.
+  // The client's resume loop compacts cleared slots once the index grows.
+  if (runningIdx < client[kPendingIdx] && queue[runningIdx] === request) {
+    queue[runningIdx] = null
+    client[kRunningIdx] = runningIdx + 1
+    return
+  }
+
+  const index = queue.indexOf(request, runningIdx)
+
+  if (index === -1 || index >= client[kPendingIdx]) {
+    return
+  }
+
+  queue.splice(index, 1)
+  client[kPendingIdx]--
+
+  if (resetPendingIdx && client[kPendingIdx] < client[kRunningIdx]) {
+    client[kPendingIdx] = client[kRunningIdx]
+  }
+}
+
 function onHttp2SessionGoAway (errorCode) {
   // TODO(mcollina): Verify if GOAWAY implements the spec correctly:
   // https://datatracker.ietf.org/doc/html/rfc7540#section-6.8
@@ -39396,7 +39471,9 @@ function onHttp2SessionGoAway (errorCode) {
   if (client[kRunningIdx] < client[kQueue].length) {
     const request = client[kQueue][client[kRunningIdx]]
     client[kQueue][client[kRunningIdx]++] = null
-    util.errorRequest(client, request, err)
+    if (request != null) {
+      util.errorRequest(client, request, err)
+    }
     client[kPendingIdx] = client[kRunningIdx]
   }
 
@@ -39429,7 +39506,9 @@ function onHttp2SessionClose () {
     const requests = client[kQueue].splice(client[kRunningIdx])
     for (let i = 0; i < requests.length; i++) {
       const request = requests[i]
-      util.errorRequest(client, request, err)
+      if (request != null) {
+        util.errorRequest(client, request, err)
+      }
     }
   }
 }
@@ -39477,7 +39556,10 @@ function shouldSendContentLength (method) {
 }
 
 function writeH2 (client, request) {
-  const requestTimeout = request.bodyTimeout ?? client[kBodyTimeout]
+  // Time to the response headers, then time between body chunks. Using
+  // bodyTimeout for both made headersTimeout a no-op over HTTP/2.
+  const headersTimeout = request.headersTimeout ?? client[kHeadersTimeout]
+  const bodyTimeout = request.bodyTimeout ?? client[kBodyTimeout]
   const session = client[kHTTP2Session]
   const { method, path, host, upgrade, expectContinue, signal, protocol, headers: reqHeaders } = request
   let { body } = request
@@ -39544,6 +39626,7 @@ function writeH2 (client, request) {
 
       // We move the running index to the next request
       client[kOnError](err)
+      completeRequest(client, request)
       client[kResume]()
     }
 
@@ -39591,14 +39674,18 @@ function writeH2 (client, request) {
 
       stream = session.request(headers, { endStream: false, signal })
       stream[kHTTP2Stream] = true
+      ++session[kOpenStreams]
 
       stream.once('response', (headers, _flags) => {
         const { [HTTP2_HEADER_STATUS]: statusCode, ...realHeaders } = headers
 
-        request.onUpgrade(statusCode, parseH2Headers(realHeaders), stream)
-
-        ++session[kOpenStreams]
-        client[kQueue][client[kRunningIdx]++] = null
+        try {
+          request.onUpgrade(statusCode, parseH2Headers(realHeaders), stream)
+        } catch (err) {
+          abort(err)
+          return
+        }
+        completeRequest(client, request)
       })
 
       stream.on('error', () => {
@@ -39615,7 +39702,7 @@ function writeH2 (client, request) {
         if (session[kOpenStreams] === 0) session.unref()
       })
 
-      stream.setTimeout(requestTimeout)
+      stream.setTimeout(headersTimeout)
       return true
     }
 
@@ -39626,18 +39713,24 @@ function writeH2 (client, request) {
     // We disabled endStream to allow the user to write to the stream
     stream = session.request(headers, { endStream: false, signal })
     stream[kHTTP2Stream] = true
+    ++session[kOpenStreams]
     stream.on('response', headers => {
       const { [HTTP2_HEADER_STATUS]: statusCode, ...realHeaders } = headers
 
-      request.onUpgrade(statusCode, parseH2Headers(realHeaders), stream)
-      ++session[kOpenStreams]
-      client[kQueue][client[kRunningIdx]++] = null
+      try {
+        request.onUpgrade(statusCode, parseH2Headers(realHeaders), stream)
+      } catch (err) {
+        abort(err)
+        return
+      }
+      completeRequest(client, request)
     })
+    stream.on('error', abort)
     stream.once('close', () => {
       session[kOpenStreams] -= 1
       if (session[kOpenStreams] === 0) session.unref()
     })
-    stream.setTimeout(requestTimeout)
+    stream.setTimeout(headersTimeout)
 
     return true
   }
@@ -39738,7 +39831,7 @@ function writeH2 (client, request) {
 
   // Increment counter as we have new streams open
   ++session[kOpenStreams]
-  stream.setTimeout(requestTimeout)
+  stream.setTimeout(headersTimeout)
 
   // Track whether we received a response (headers)
   let responseReceived = false
@@ -39747,6 +39840,7 @@ function writeH2 (client, request) {
     const { [HTTP2_HEADER_STATUS]: statusCode, ...realHeaders } = headers
     request.onResponseStarted()
     responseReceived = true
+    stream.setTimeout(bodyTimeout)
 
     // Due to the stream nature, it is possible we face a race condition
     // where the stream has been assigned, but the request has been aborted
@@ -39781,14 +39875,13 @@ function writeH2 (client, request) {
         request.onComplete({})
       }
 
-      client[kQueue][client[kRunningIdx]++] = null
+      completeRequest(client, request)
       client[kResume]()
     } else {
       // Stream ended without receiving a response - this is an error
       // (e.g., server destroyed the stream before sending headers)
       abort(new InformationalError('HTTP/2: stream half-closed (remote)'))
-      client[kQueue][client[kRunningIdx]++] = null
-      client[kPendingIdx] = client[kRunningIdx]
+      completeRequest(client, request, true)
       client[kResume]()
     }
   })
@@ -39799,6 +39892,14 @@ function writeH2 (client, request) {
     if (session[kOpenStreams] === 0) {
       session.unref()
     }
+
+    // A stream can close without ever emitting 'end' or 'error': a peer's
+    // RST_STREAM(CANCEL) received before the response is reported by Node as a
+    // bare 'close', and destroying the stream unenrolls its timeout, so no
+    // 'timeout' follows either. Nothing else would ever settle this request.
+    if (!request.aborted && !request.completed) {
+      abort(new InformationalError('HTTP/2: stream closed before the response was complete'))
+    }
   })
 
   stream.once('error', function (err) {
@@ -39816,7 +39917,9 @@ function writeH2 (client, request) {
   })
 
   stream.on('timeout', () => {
-    const err = new InformationalError(`HTTP/2: "stream timeout after ${requestTimeout}"`)
+    const err = responseReceived
+      ? new BodyTimeoutError(`HTTP/2: "body timeout after ${bodyTimeout}"`)
+      : new HeadersTimeoutError(`HTTP/2: "headers timeout after ${headersTimeout}"`)
     stream.removeAllListeners('data')
     session[kOpenStreams] -= 1
 
@@ -40438,7 +40541,9 @@ class Client extends DispatcherBase {
       const requests = this[kQueue].splice(this[kPendingIdx])
       for (let i = 0; i < requests.length; i++) {
         const request = requests[i]
-        util.errorRequest(this, request, err)
+        if (request != null) {
+          util.errorRequest(this, request, err)
+        }
       }
 
       const callback = () => {
@@ -40477,7 +40582,9 @@ function onError (client, err) {
 
     for (let i = 0; i < requests.length; i++) {
       const request = requests[i]
-      util.errorRequest(client, request, err)
+      if (request != null) {
+        util.errorRequest(client, request, err)
+      }
     }
     assert(client[kSize] === 0)
   }
@@ -42786,6 +42893,13 @@ class CacheHandler {
     }
 
     const cacheControlHeader = resHeaders['cache-control']
+    const cacheControlDirectives = cacheControlHeader ? parseCacheControlHeader(cacheControlHeader) : {}
+
+    if (revalidationResponseDisallowsCachedReuse(this.#cacheType, resHeaders, cacheControlDirectives)) {
+      deleteCachedValue(this.#store, this.#cacheKey)
+      return downstreamOnHeaders()
+    }
+
     const heuristicallyCacheable = resHeaders['last-modified'] && arrayIncludes(HEURISTICALLY_CACHEABLE_STATUS_CODES, statusCode)
     if (
       !cacheControlHeader &&
@@ -42802,8 +42916,7 @@ class CacheHandler {
       return downstreamOnHeaders()
     }
 
-    const cacheControlDirectives = cacheControlHeader ? parseCacheControlHeader(cacheControlHeader) : {}
-    if (!canCacheResponse(this.#cacheType, statusCode, resHeaders, cacheControlDirectives, this.#cacheKey.headers)) {
+    if (!canCacheResponse(this.#cacheType, this.#cacheKey.method, statusCode, resHeaders, cacheControlDirectives, this.#cacheKey.headers)) {
       if (statusCode === 304 && (cacheControlHeader || revalidationResponseDisallowsCachedReuse(this.#cacheType, resHeaders, cacheControlDirectives))) {
         deleteCachedValue(this.#store, this.#cacheKey)
       }
@@ -43044,7 +43157,10 @@ function deleteCachedValueIfNotModified (statusCode, store, cacheKey) {
  */
 function revalidationResponseDisallowsCachedReuse (cacheType, resHeaders, cacheControlDirectives) {
   return cacheControlDirectives['no-store'] === true ||
-    (cacheType === 'shared' && cacheControlDirectives.private === true) ||
+    (cacheType === 'shared' && (
+      cacheControlDirectives.private === true ||
+      Object.hasOwn(resHeaders, 'set-cookie')
+    )) ||
     (resHeaders.vary ? isInvalidOrWildcardVaryHeader(resHeaders.vary) : false)
 }
 
@@ -43052,12 +43168,16 @@ function revalidationResponseDisallowsCachedReuse (cacheType, resHeaders, cacheC
  * @see https://www.rfc-editor.org/rfc/rfc9111.html#name-storing-responses-to-authen
  *
  * @param {import('../../types/cache-interceptor.d.ts').default.CacheOptions['type']} cacheType
+ * @param {string} method
  * @param {number} statusCode
  * @param {import('../../types/header.d.ts').IncomingHttpHeaders} resHeaders
  * @param {import('../../types/cache-interceptor.d.ts').default.CacheControlDirectives} cacheControlDirectives
  * @param {import('../../types/header.d.ts').IncomingHttpHeaders} [reqHeaders]
  */
-function canCacheResponse (cacheType, statusCode, resHeaders, cacheControlDirectives, reqHeaders) {
+function canCacheResponse (cacheType, method, statusCode, resHeaders, cacheControlDirectives, reqHeaders) {
+  if (!arrayIncludes(util.safeHTTPMethods, method)) {
+    return false
+  }
   // Status code must be final and understood.
   if (statusCode < 200 || arrayIncludes(NOT_UNDERSTOOD_STATUS_CODES, statusCode)) {
     return false
@@ -43078,7 +43198,10 @@ function canCacheResponse (cacheType, statusCode, resHeaders, cacheControlDirect
     return false
   }
 
-  if (cacheType === 'shared' && cacheControlDirectives.private === true) {
+  if (cacheType === 'shared' && (
+    cacheControlDirectives.private === true ||
+    Object.hasOwn(resHeaders, 'set-cookie')
+  )) {
     return false
   }
 
@@ -44303,6 +44426,55 @@ function validatePartialResponseContentLength (headers, range, statusCode, retry
   }
 }
 
+// A stable controller handed to the downstream handler for the lifetime of the
+// request. Each transparent retry/resume is a separate dispatch with its own
+// connection controller. The proxy always forwards to the active connection
+// while preserving a downstream pause across controller replacement.
+class RetryController {
+  #paused = false
+  #target = null
+
+  set target (target) {
+    this.#target = target
+    if (this.#paused) {
+      target?.pause()
+    }
+  }
+
+  get target () { return this.#target }
+
+  pause () {
+    this.#paused = true
+    this.#target?.pause()
+  }
+
+  resume () {
+    this.#paused = false
+    this.#target?.resume()
+  }
+
+  abort (reason) {
+    this.#target?.abort(reason)
+  }
+
+  get paused () { return this.#paused || (this.#target?.paused ?? false) }
+  get aborted () { return this.#target?.aborted ?? false }
+  get reason () { return this.#target?.reason ?? null }
+  get rawHeaders () { return this.#target?.rawHeaders ?? null }
+  set rawHeaders (value) {
+    if (this.#target) {
+      this.#target.rawHeaders = value
+    }
+  }
+
+  get rawTrailers () { return this.#target?.rawTrailers ?? null }
+  set rawTrailers (value) {
+    if (this.#target) {
+      this.#target.rawTrailers = value
+    }
+  }
+}
+
 class RetryHandler {
   constructor (opts, { dispatch, handler }) {
     const { retryOptions, ...dispatchOpts } = opts
@@ -44357,14 +44529,23 @@ class RetryHandler {
     this.start = 0
     this.end = null
     this.etag = null
+    this.controllerProxy = new RetryController()
   }
 
   onResponseStartWithRetry (controller, statusCode, headers, statusMessage, err) {
     if (this.retryOpts.throwOnError) {
       // Preserve old behavior for status codes that are not eligible for retry
       if (this.retryOpts.statusCodes.includes(statusCode) === false) {
-        this.headersSent = true
-        this.handler.onResponseStart?.(controller, statusCode, headers, statusMessage)
+        if (this.headersSent) {
+          // The downstream handler already received the response from an
+          // earlier attempt. Forwarding this response would replace the
+          // downstream body and leave the original body pending forever.
+          this.handler.onResponseError?.(this.controllerProxy, err)
+        } else {
+          this.headersSent = true
+          this.checkpointResponseEnd(headers)
+          this.handler.onResponseStart?.(this.controllerProxy, statusCode, headers, statusMessage)
+        }
       } else {
         this.error = err
       }
@@ -44374,14 +44555,23 @@ class RetryHandler {
 
     if (isDisturbed(this.opts.body)) {
       this.headersSent = true
-      this.handler.onResponseStart?.(controller, statusCode, headers, statusMessage)
+      this.checkpointResponseEnd(headers)
+      this.handler.onResponseStart?.(this.controllerProxy, statusCode, headers, statusMessage)
       return
     }
 
     function shouldRetry (passedErr) {
       if (passedErr) {
-        this.headersSent = true
-        this.handler.onResponseStart?.(controller, statusCode, headers, statusMessage)
+        if (this.headersSent) {
+          // The downstream handler already received the response from an
+          // earlier attempt. Forwarding this response would replace the
+          // downstream body and leave the original body pending forever.
+          this.handler.onResponseError?.(this.controllerProxy, passedErr)
+        } else {
+          this.headersSent = true
+          this.checkpointResponseEnd(headers)
+          this.handler.onResponseStart?.(this.controllerProxy, statusCode, headers, statusMessage)
+        }
         controller.resume()
         return
       }
@@ -44401,14 +44591,29 @@ class RetryHandler {
     )
   }
 
-  onRequestStart (controller, context) {
-    if (!this.headersSent) {
-      this.handler.onRequestStart?.(controller, context)
+  checkpointResponseEnd (headers) {
+    if (this.end == null && this.opts.method !== 'HEAD') {
+      const contentLength = headers['content-length']
+      this.end = contentLength != null ? Number(contentLength) - 1 : null
+
+      assert(
+        this.end == null || Number.isFinite(this.end),
+        'invalid content-length'
+      )
+
+      this.resume = this.end != null
     }
   }
 
-  onRequestUpgrade (controller, statusCode, headers, socket) {
-    this.handler.onRequestUpgrade?.(controller, statusCode, headers, socket)
+  onRequestStart (controller, context) {
+    this.controllerProxy.target = controller
+    if (!this.headersSent) {
+      this.handler.onRequestStart?.(this.controllerProxy, context)
+    }
+  }
+
+  onRequestUpgrade (_controller, statusCode, headers, socket) {
+    this.handler.onRequestUpgrade?.(this.controllerProxy, statusCode, headers, socket)
   }
 
   static [kRetryHandlerDefaultRetry] (err, { state, opts }, cb) {
@@ -44521,8 +44726,12 @@ class RetryHandler {
 
       const { start, size, end = size ? size - 1 : null } = contentRange
 
-      assert(this.start === start, 'content-range mismatch')
-      assert(this.end == null || this.end === end, 'content-range mismatch')
+      if (this.start !== start || (this.end != null && this.end !== end)) {
+        throw new RequestRetryError('Content-Range mismatch', statusCode, {
+          headers,
+          data: { count: this.retryCount }
+        })
+      }
 
       return
     }
@@ -44535,7 +44744,7 @@ class RetryHandler {
         if (range == null) {
           this.headersSent = true
           this.handler.onResponseStart?.(
-            controller,
+            this.controllerProxy,
             statusCode,
             headers,
             statusMessage
@@ -44584,7 +44793,7 @@ class RetryHandler {
 
       this.headersSent = true
       this.handler.onResponseStart?.(
-        controller,
+        this.controllerProxy,
         statusCode,
         headers,
         statusMessage
@@ -44597,30 +44806,30 @@ class RetryHandler {
     }
   }
 
-  onResponseData (controller, chunk) {
+  onResponseData (_controller, chunk) {
     if (this.error) {
       return
     }
 
     this.start += chunk.length
 
-    this.handler.onResponseData?.(controller, chunk)
+    this.handler.onResponseData?.(this.controllerProxy, chunk)
   }
 
-  onResponseEnd (controller, trailers) {
+  onResponseEnd (_controller, trailers) {
     if (this.error && this.retryOpts.throwOnError) {
       throw this.error
     }
 
     if (!this.error) {
       this.retryCount = 0
-      return this.handler.onResponseEnd?.(controller, trailers)
+      return this.handler.onResponseEnd?.(this.controllerProxy, trailers)
     }
 
-    this.retry(controller)
+    this.retry()
   }
 
-  retry (controller) {
+  retry () {
     if (this.start !== 0) {
       const headers = { range: `bytes=${this.start}-${this.end ?? ''}` }
 
@@ -44642,23 +44851,23 @@ class RetryHandler {
       this.retryCountCheckpoint = this.retryCount
       this.dispatch(this.opts, this)
     } catch (err) {
-      this.handler.onResponseError?.(controller, err)
+      this.handler.onResponseError?.(this.controllerProxy, err)
     }
   }
 
   onResponseError (controller, err) {
-    if (controller?.aborted || isDisturbed(this.opts.body)) {
-      this.handler.onResponseError?.(controller, err)
+    if (controller?.aborted || isDisturbed(this.opts.body) || (this.headersSent && !this.resume)) {
+      this.handler.onResponseError?.(this.controllerProxy, err)
       return
     }
 
     function shouldRetry (returnedErr) {
       if (!returnedErr) {
-        this.retry(controller)
+        this.retry()
         return
       }
 
-      this.handler?.onResponseError?.(controller, returnedErr)
+      this.handler?.onResponseError?.(this.controllerProxy, returnedErr)
     }
 
     // We reconcile in case of a mix between network errors
@@ -45038,7 +45247,10 @@ function staleResponseRequiresRevalidation (result, cacheType) {
  * @returns {boolean}
  */
 function revalidationResponseDisallowsCachedReuse (cacheType, headers) {
-  if (headers.vary && isInvalidOrWildcardVaryHeader(headers.vary)) {
+  if (
+    (headers.vary && isInvalidOrWildcardVaryHeader(headers.vary)) ||
+    (cacheType === 'shared' && Object.hasOwn(headers, 'set-cookie'))
+  ) {
     return true
   }
 
@@ -45297,6 +45509,17 @@ function handleResult (
     return handleUncachedResponse(dispatch, globalOpts, cacheKey, handler, opts, reqCacheControl)
   }
 
+  // Shared stores may outlive the Undici version that wrote them. Do not
+  // re-serve a Set-Cookie header from an existing shared-cache entry.
+  if (globalOpts.type === 'shared' && Object.hasOwn(result.headers, 'set-cookie')) {
+    if (util.isStream(result.body)) {
+      result.body.on('error', nop).destroy()
+    }
+
+    deleteCachedValue(globalOpts.store, cacheKey)
+    return handleUncachedResponse(dispatch, globalOpts, cacheKey, handler, opts, reqCacheControl)
+  }
+
   const now = Date.now()
   if (now > result.deleteAt) {
     // Response is expired, cache store shouldn't have given this to us
@@ -45495,6 +45718,11 @@ module.exports = (opts = {}) => {
        * @type {import('../../types/cache-interceptor.d.ts').default.CacheKey}
        */
       const cacheKey = makeCacheKey(opts)
+
+      if (!arrayIncludes(util.safeHTTPMethods, opts.method)) {
+        return dispatch(opts, new CacheHandler(globalOpts, cacheKey, handler))
+      }
+
       const result = store.get(cacheKey)
 
       if (result && typeof result.then === 'function') {
@@ -45532,7 +45760,8 @@ module.exports = (opts = {}) => {
 
 
 const { createInflate, createGunzip, createBrotliDecompress, createZstdDecompress } = __nccwpck_require__(38522)
-const { pipeline } = __nccwpck_require__(57075)
+const { pipeline, Transform: TransformStream } = __nccwpck_require__(57075)
+const { InvalidArgumentError, ResponseExceededMaxSizeError } = __nccwpck_require__(68707)
 const DecoratorHandler = __nccwpck_require__(58155)
 const { runtimeFeatures } = __nccwpck_require__(313)
 
@@ -45540,6 +45769,60 @@ const { runtimeFeatures } = __nccwpck_require__(313)
 /** @typedef {import('node:stream').Transform} Controller */
 /** @typedef {Transform&import('node:zlib').Zlib} DecompressorStream */
 
+class DecompressController {
+  #onPause
+  #onResume
+  #onAbort
+  #paused = false
+
+  constructor (onPause, onResume, onAbort) {
+    this.#onPause = onPause
+    this.#onResume = onResume
+    this.#onAbort = onAbort
+    this.target = null
+  }
+
+  pause () {
+    if (this.#paused) {
+      return
+    }
+
+    this.#paused = true
+    this.#onPause()
+  }
+
+  resume () {
+    if (!this.#paused) {
+      return
+    }
+
+    this.#paused = false
+    this.#onResume()
+  }
+
+  abort (reason) {
+    this.target?.abort(reason)
+    this.#onAbort(reason)
+  }
+
+  get paused () { return this.#paused }
+  get aborted () { return this.target?.aborted ?? false }
+  get reason () { return this.target?.reason ?? null }
+  get rawHeaders () { return this.target?.rawHeaders ?? null }
+  set rawHeaders (value) {
+    if (this.target) {
+      this.target.rawHeaders = value
+    }
+  }
+
+  get rawTrailers () { return this.target?.rawTrailers ?? null }
+  set rawTrailers (value) {
+    if (this.target) {
+      this.target.rawTrailers = value
+    }
+  }
+}
+
 /** @type {Record<string, () => DecompressorStream>} */
 const supportedEncodings = {
   gzip: createGunzip,
@@ -45552,6 +45835,31 @@ const supportedEncodings = {
 }
 
 const defaultSkipStatusCodes = /** @type {const} */ ([204, 304])
+const defaultMaxSize = 0
+
+/**
+ * Limits the output of one stage in a decompression chain.
+ * @param {number} maxSize - Maximum output size in bytes
+ * @returns {Transform}
+ */
+function createMaxSizeLimiter (maxSize) {
+  let size = 0
+
+  return new TransformStream({
+    transform (chunk, _encoding, callback) {
+      const decompressedSize = size + chunk.length
+      if (decompressedSize > maxSize) {
+        callback(new ResponseExceededMaxSizeError(
+          `Decompressed response size (${decompressedSize}) exceeded maxSize (${maxSize})`
+        ))
+        return
+      }
+
+      size = decompressedSize
+      callback(null, chunk)
+    }
+  })
+}
 
 let warningEmitted = /** @type {boolean} */ (false)
 
@@ -45559,20 +45867,150 @@ let warningEmitted = /** @type {boolean} */ (false)
  * @typedef {Object} DecompressHandlerOptions
  * @property {number[]|Readonly<number[]>} [skipStatusCodes=[204, 304]] - List of status codes to skip decompression for
  * @property {boolean} [skipErrorResponses] - Whether to skip decompression for error responses (status codes >= 400)
+ * @property {number} [maxSize=0] - Maximum decompressed response size in bytes. 0 disables the limit
  */
 
 class DecompressHandler extends DecoratorHandler {
   /** @type {Transform[]} */
   #decompressors = []
+  /** @type {Record<string, string | string[]> | undefined} */
+  #trailers
   /** @type {Readonly<number[]>} */
   #skipStatusCodes
   /** @type {boolean} */
   #skipErrorResponses
+  /** @type {number} */
+  #maxSize
+  /** @type {number} */
+  #decompressedSize = 0
+  /** @type {boolean} */
+  #terminated = false
+  /** @type {boolean} */
+  #inputEnded = false
+  /** @type {boolean} */
+  #inputBackpressured = false
+  /** @type {boolean} */
+  #upstreamPaused = false
+  /** @type {boolean} */
+  #draining = false
+  /** @type {boolean} */
+  #drainRequested = false
+  /** @type {boolean} */
+  #completionPending = false
+  /** @type {DecompressorStream | undefined} */
+  #finalDecompressor
+  /** @type {DecompressController} */
+  #controller
+
+  constructor (handler, { skipStatusCodes = defaultSkipStatusCodes, skipErrorResponses = true, maxSize = defaultMaxSize } = {}) {
+    if (!Number.isSafeInteger(maxSize) || maxSize < 0) {
+      throw new InvalidArgumentError('maxSize must be a non-negative integer')
+    }
 
-  constructor (handler, { skipStatusCodes = defaultSkipStatusCodes, skipErrorResponses = true } = {}) {
     super(handler)
     this.#skipStatusCodes = skipStatusCodes
     this.#skipErrorResponses = skipErrorResponses
+    this.#maxSize = maxSize
+    this.#controller = new DecompressController(
+      () => this.#onDownstreamPause(),
+      () => this.#onDownstreamResume(),
+      reason => {
+        if (this.#inputEnded && !this.#terminated) {
+          this.onResponseError(this.#controller, reason)
+        }
+      }
+    )
+  }
+
+  #onDownstreamPause () {
+    this.#pauseUpstream()
+  }
+
+  #onDownstreamResume () {
+    const drainWasDeferred = this.#draining
+    this.#drainOutput()
+    if (!drainWasDeferred) {
+      this.#resumeUpstreamIfNeeded()
+      this.#finishIfReady()
+    }
+  }
+
+  #pauseUpstream () {
+    if (!this.#upstreamPaused && !this.#terminated) {
+      this.#upstreamPaused = true
+      this.#controller.target?.pause()
+    }
+  }
+
+  #resumeUpstreamIfNeeded () {
+    if (this.#upstreamPaused && !this.#controller.paused && !this.#inputBackpressured) {
+      this.#upstreamPaused = false
+      if (!this.#inputEnded) {
+        this.#controller.target?.resume()
+      }
+    }
+  }
+
+  #drainOutput () {
+    if (this.#terminated || this.#controller.paused || !this.#finalDecompressor) {
+      return
+    }
+
+    if (this.#draining) {
+      this.#drainRequested = true
+      return
+    }
+
+    this.#draining = true
+    try {
+      do {
+        this.#drainRequested = false
+        let chunk
+        while (!this.#terminated && !this.#controller.paused && (chunk = this.#finalDecompressor.read()) !== null) {
+          if (this.#maxSize > 0) {
+            const decompressedSize = this.#decompressedSize + chunk.length
+            if (decompressedSize > this.#maxSize) {
+              this.#fail(new ResponseExceededMaxSizeError(
+                `Decompressed response size (${decompressedSize}) exceeded maxSize (${this.#maxSize})`
+              ))
+              return
+            }
+
+            this.#decompressedSize = decompressedSize
+          }
+
+          const result = super.onResponseData(this.#controller, chunk)
+          if (result === false && !this.#controller.paused) {
+            this.#controller.pause()
+          }
+        }
+      } while (this.#drainRequested && !this.#terminated && !this.#controller.paused)
+    } finally {
+      this.#draining = false
+    }
+
+    this.#resumeUpstreamIfNeeded()
+    this.#finishIfReady()
+  }
+
+  #finishIfReady () {
+    if (this.#terminated || !this.#completionPending || this.#controller.paused || this.#draining) {
+      return
+    }
+
+    this.#terminated = true
+    this.#cleanupDecompressors()
+    super.onResponseEnd(this.#controller, this.#trailers)
+  }
+
+  #onDecompressionEnd () {
+    if (this.#terminated) {
+      return
+    }
+
+    this.#completionPending = true
+    this.#drainOutput()
+    this.#finishIfReady()
   }
 
   /**
@@ -45592,7 +46030,7 @@ class DecompressHandler extends DecoratorHandler {
    * Creates a chain of decompressors for multiple content encodings
    *
    * @param {string} encodings - Comma-separated list of content encodings
-   * @returns {Array<DecompressorStream>} - Array of decompressor streams
+   * @returns {Array<Transform>} - Array of decompressor and limiting streams
    * @throws {Error} - If the number of content-encodings exceeds the maximum allowed
    */
   #createDecompressionChain (encodings) {
@@ -45620,60 +46058,97 @@ class DecompressHandler extends DecoratorHandler {
       decompressors.push(supportedEncodings[encoding]())
     }
 
-    return decompressors
+    if (decompressors.length < 2) {
+      return decompressors
+    }
+
+    /** @type {Transform[]} */
+    const streams = []
+    for (let i = 0; i < decompressors.length; i++) {
+      streams.push(decompressors[i])
+      if (i < decompressors.length - 1 && this.#maxSize > 0) {
+        streams.push(createMaxSizeLimiter(this.#maxSize))
+      }
+    }
+
+    return streams
   }
 
   /**
-   * Sets up event handlers for a decompressor stream using readable events
-   * @param {DecompressorStream} decompressor - The decompressor stream
-   * @param {Controller} controller - The controller to coordinate with
+   * Stops decompression and reports an error.
+   * @param {Error} error - The decompression error
    * @returns {void}
    */
-  #setupDecompressorEvents (decompressor, controller) {
-    decompressor.on('readable', () => {
-      let chunk
-      while ((chunk = decompressor.read()) !== null) {
-        const result = super.onResponseData(controller, chunk)
-        if (result === false) {
-          break
-        }
-      }
-    })
+  #fail (error) {
+    if (this.#terminated) {
+      return
+    }
 
-    decompressor.on('error', (error) => {
-      super.onResponseError(controller, error)
-    })
+    if (this.#inputEnded) {
+      // The request is already marked complete once the compressed input ends,
+      // so controller.abort() can no longer propagate decoder flush errors.
+      this.onResponseError(this.#controller, error)
+    } else {
+      this.#controller.abort(error)
+    }
+  }
+
+  /**
+   * Sets up event handlers for the final decompressor stream.
+   * @param {DecompressorStream} decompressor - The decompressor stream
+   * @returns {void}
+   */
+  #setupDecompressorEvents (decompressor) {
+    this.#finalDecompressor = decompressor
+    decompressor.on('readable', () => this.#drainOutput())
+    decompressor.on('error', (error) => this.#fail(error))
   }
 
   /**
    * Sets up event handling for a single decompressor
-   * @param {Controller} controller - The controller to handle events
    * @returns {void}
    */
-  #setupSingleDecompressor (controller) {
+  #setupSingleDecompressor () {
     const decompressor = this.#decompressors[0]
-    this.#setupDecompressorEvents(decompressor, controller)
+    this.#setupDecompressorEvents(decompressor)
 
-    decompressor.on('end', () => {
-      super.onResponseEnd(controller, {})
-    })
+    decompressor.on('end', () => this.#onDecompressionEnd())
   }
 
   /**
    * Sets up event handling for multiple chained decompressors using pipeline
-   * @param {Controller} controller - The controller to handle events
    * @returns {void}
    */
-  #setupMultipleDecompressors (controller) {
+  #setupMultipleDecompressors () {
     const lastDecompressor = this.#decompressors[this.#decompressors.length - 1]
-    this.#setupDecompressorEvents(lastDecompressor, controller)
+    this.#setupDecompressorEvents(lastDecompressor)
 
     pipeline(this.#decompressors, (err) => {
-      if (err) {
-        super.onResponseError(controller, err)
+      if (this.#terminated) {
         return
       }
-      super.onResponseEnd(controller, {})
+
+      if (err) {
+        this.#fail(err)
+        return
+      }
+
+      this.#onDecompressionEnd()
+    })
+  }
+
+  #setupInputBackpressure () {
+    const decompressor = this.#decompressors[0]
+    decompressor.on('drain', () => {
+      if (this.#terminated) {
+        return
+      }
+
+      this.#inputBackpressured = false
+      if (!this.#controller.paused) {
+        this.#drainOutput()
+        this.#resumeUpstreamIfNeeded()
+      }
     })
   }
 
@@ -45683,6 +46158,16 @@ class DecompressHandler extends DecoratorHandler {
    */
   #cleanupDecompressors () {
     this.#decompressors.length = 0
+    this.#finalDecompressor = undefined
+  }
+
+  onRequestStart (controller, context) {
+    this.#controller.target = controller
+    return super.onRequestStart(this.#controller, context)
+  }
+
+  onRequestUpgrade (controller, statusCode, headers, socket) {
+    return super.onRequestUpgrade(this.#controller, statusCode, headers, socket)
   }
 
   /**
@@ -45697,14 +46182,14 @@ class DecompressHandler extends DecoratorHandler {
 
     // If content encoding is not supported or status code is in skip list
     if (this.#shouldSkipDecompression(contentEncoding, statusCode)) {
-      return super.onResponseStart(controller, statusCode, headers, statusMessage)
+      return super.onResponseStart(this.#controller, statusCode, headers, statusMessage)
     }
 
     const decompressors = this.#createDecompressionChain(contentEncoding.toLowerCase())
 
     if (decompressors.length === 0) {
       this.#cleanupDecompressors()
-      return super.onResponseStart(controller, statusCode, headers, statusMessage)
+      return super.onResponseStart(this.#controller, statusCode, headers, statusMessage)
     }
 
     this.#decompressors = decompressors
@@ -45712,13 +46197,41 @@ class DecompressHandler extends DecoratorHandler {
     // Remove compression headers since we're decompressing
     const { 'content-encoding': _, 'content-length': __, ...newHeaders } = headers
 
-    if (this.#decompressors.length === 1) {
-      this.#setupSingleDecompressor(controller)
-    } else {
-      this.#setupMultipleDecompressors(controller)
+    if (this.#controller.rawHeaders) {
+      const rawHeaders = this.#controller.rawHeaders
+
+      if (Array.isArray(rawHeaders)) {
+        const filteredHeaders = []
+        for (let i = 0; i < rawHeaders.length; i += 2) {
+          const headerName = rawHeaders[i]
+          const name = Buffer.isBuffer(headerName) ? headerName.toString('latin1') : `${headerName}`
+          const lowerName = name.toLowerCase()
+
+          if (lowerName === 'content-encoding' || lowerName === 'content-length') {
+            continue
+          }
+
+          filteredHeaders.push(rawHeaders[i], rawHeaders[i + 1])
+        }
+        rawHeaders.splice(0, rawHeaders.length, ...filteredHeaders)
+      } else if (typeof rawHeaders === 'object') {
+        for (const name of Object.keys(rawHeaders)) {
+          const lowerName = name.toLowerCase()
+          if (lowerName === 'content-encoding' || lowerName === 'content-length') {
+            delete rawHeaders[name]
+          }
+        }
+      }
     }
 
-    return super.onResponseStart(controller, statusCode, newHeaders, statusMessage)
+    this.#setupInputBackpressure()
+    if (this.#decompressors.length === 1) {
+      this.#setupSingleDecompressor()
+    } else {
+      this.#setupMultipleDecompressors()
+    }
+
+    return super.onResponseStart(this.#controller, statusCode, newHeaders, statusMessage)
   }
 
   /**
@@ -45728,10 +46241,13 @@ class DecompressHandler extends DecoratorHandler {
    */
   onResponseData (controller, chunk) {
     if (this.#decompressors.length > 0) {
-      this.#decompressors[0].write(chunk)
+      if (!this.#decompressors[0].write(chunk)) {
+        this.#inputBackpressured = true
+        this.#pauseUpstream()
+      }
       return
     }
-    super.onResponseData(controller, chunk)
+    return super.onResponseData(this.#controller, chunk)
   }
 
   /**
@@ -45741,11 +46257,12 @@ class DecompressHandler extends DecoratorHandler {
    */
   onResponseEnd (controller, trailers) {
     if (this.#decompressors.length > 0) {
+      this.#inputEnded = true
+      this.#trailers = trailers
       this.#decompressors[0].end()
-      this.#cleanupDecompressors()
       return
     }
-    super.onResponseEnd(controller, trailers)
+    return super.onResponseEnd(this.#controller, trailers)
   }
 
   /**
@@ -45754,13 +46271,16 @@ class DecompressHandler extends DecoratorHandler {
    * @returns {void}
    */
   onResponseError (controller, err) {
-    if (this.#decompressors.length > 0) {
-      for (const decompressor of this.#decompressors) {
-        decompressor.destroy(err)
-      }
-      this.#cleanupDecompressors()
+    if (this.#terminated) {
+      return
     }
-    super.onResponseError(controller, err)
+
+    this.#terminated = true
+    for (const decompressor of this.#decompressors) {
+      decompressor.destroy()
+    }
+    this.#cleanupDecompressors()
+    super.onResponseError(this.#controller, err)
   }
 }
 
@@ -46509,7 +47029,6 @@ class DumpHandler extends DecoratorHandler {
   #maxSize = 1024 * 1024
   #dumped = false
   #size = 0
-  #controller = null
   aborted = false
   reason = false
 
@@ -46531,7 +47050,6 @@ class DumpHandler extends DecoratorHandler {
 
   onRequestStart (controller, context) {
     controller.abort = this.#abort.bind(this)
-    this.#controller = controller
 
     return super.onRequestStart(controller, context)
   }
@@ -46555,43 +47073,32 @@ class DumpHandler extends DecoratorHandler {
   }
 
   onResponseError (controller, err) {
-    if (this.#dumped) {
-      return
-    }
-
-    // On network errors before connect, controller will be null
-    err = this.#controller?.reason ?? err
-
-    super.onResponseError(controller, err)
+    super.onResponseError(controller, this.aborted === true ? this.reason : err)
   }
 
   onResponseData (controller, chunk) {
     this.#size = this.#size + chunk.length
 
-    if (this.#size >= this.#maxSize) {
-      this.#dumped = true
+    if (this.#size > this.#maxSize) {
+      throw new RequestAbortedError(
+        `Response size (${this.#size}) larger than maxSize (${this.#maxSize})`
+      )
+    }
 
-      if (this.aborted === true) {
-        super.onResponseError(controller, this.reason)
-      } else {
-        super.onResponseEnd(controller, {})
-      }
+    if (this.#size === this.#maxSize) {
+      this.#dumped = true
     }
 
     return true
   }
 
   onResponseEnd (controller, trailers) {
-    if (this.#dumped) {
-      return
-    }
-
-    if (this.#controller.aborted === true) {
+    if (this.aborted === true) {
       super.onResponseError(controller, this.reason)
       return
     }
 
-    super.onResponseEnd(controller, trailers)
+    super.onResponseEnd(controller, this.#dumped ? {} : trailers)
   }
 }
 
@@ -54018,6 +54525,49 @@ const COLON = 0x3A
  */
 const SPACE = 0x20
 
+const DATA = Buffer.from('data')
+const EVENT = Buffer.from('event')
+const ID = Buffer.from('id')
+const RETRY = Buffer.from('retry')
+
+function isASCIINumberBytes (buffer, start) {
+  if (start >= buffer.length) {
+    return false
+  }
+
+  for (let i = start; i < buffer.length; i++) {
+    if (buffer[i] < 0x30 || buffer[i] > 0x39) {
+      return false
+    }
+  }
+
+  return true
+}
+
+function isValidLastEventIdBytes (buffer, start) {
+  for (let i = start; i < buffer.length; i++) {
+    if (buffer[i] === 0x00) {
+      return false
+    }
+  }
+
+  return true
+}
+
+function isFieldName (line, length, field) {
+  if (length !== field.length) {
+    return false
+  }
+
+  for (let i = 0; i < length; i++) {
+    if (line[i] !== field[i]) {
+      return false
+    }
+  }
+
+  return true
+}
+
 /**
  * @typedef {object} EventSourceStreamEvent
  * @type {object}
@@ -54058,11 +54608,14 @@ class EventSourceStream extends Transform {
   eventEndCheck = false
 
   /**
-   * @type {Buffer|null}
+   * @type {Buffer[]}
    */
-  buffer = null
+  chunks = []
 
+  chunkIndex = 0
   pos = 0
+  lineChunkIndex = 0
+  linePos = 0
 
   event = {
     data: undefined,
@@ -54102,92 +54655,20 @@ class EventSourceStream extends Transform {
       return
     }
 
-    // Cache the chunk in the buffer, as the data might not be complete while
-    // processing it
-    // TODO: Investigate if there is a more performant way to handle
-    // incoming chunks
-    // see: https://github.com/nodejs/undici/issues/2630
-    if (this.buffer) {
-      this.buffer = Buffer.concat([this.buffer, chunk])
-    } else {
-      this.buffer = chunk
-    }
+    this.chunks.push(chunk)
 
     // Strip leading byte-order-mark if we opened the stream and started
     // the processing of the incoming data
     if (this.checkBOM) {
-      switch (this.buffer.length) {
-        case 1:
-          // Check if the first byte is the same as the first byte of the BOM
-          if (this.buffer[0] === BOM[0]) {
-            // If it is, we need to wait for more data
-            callback()
-            return
-          }
-          // Set the checkBOM flag to false as we don't need to check for the
-          // BOM anymore
-          this.checkBOM = false
-
-          // The buffer only contains one byte so we need to wait for more data
-          callback()
-          return
-        case 2:
-          // Check if the first two bytes are the same as the first two bytes
-          // of the BOM
-          if (
-            this.buffer[0] === BOM[0] &&
-            this.buffer[1] === BOM[1]
-          ) {
-            // If it is, we need to wait for more data, because the third byte
-            // is needed to determine if it is the BOM or not
-            callback()
-            return
-          }
-
-          // Set the checkBOM flag to false as we don't need to check for the
-          // BOM anymore
-          this.checkBOM = false
-          break
-        case 3:
-          // Check if the first three bytes are the same as the first three
-          // bytes of the BOM
-          if (
-            this.buffer[0] === BOM[0] &&
-            this.buffer[1] === BOM[1] &&
-            this.buffer[2] === BOM[2]
-          ) {
-            // If it is, we can drop the buffered data, as it is only the BOM
-            this.buffer = Buffer.alloc(0)
-            // Set the checkBOM flag to false as we don't need to check for the
-            // BOM anymore
-            this.checkBOM = false
-
-            // Await more data
-            callback()
-            return
-          }
-          // If it is not the BOM, we can start processing the data
-          this.checkBOM = false
-          break
-        default:
-          // The buffer is longer than 3 bytes, so we can drop the BOM if it is
-          // present
-          if (
-            this.buffer[0] === BOM[0] &&
-            this.buffer[1] === BOM[1] &&
-            this.buffer[2] === BOM[2]
-          ) {
-            // Remove the BOM from the buffer
-            this.buffer = this.buffer.subarray(3)
-          }
-
-          // Set the checkBOM flag to false as we don't need to check for the
-          this.checkBOM = false
-          break
+      if (this.handleBOM()) {
+        callback()
+        return
       }
     }
 
-    while (this.pos < this.buffer.length) {
+    while (this.hasCurrentByte()) {
+      const byte = this.currentByte()
+
       // If the previous line ended with an end-of-line, we need to check
       // if the next character is also an end-of-line.
       if (this.eventEndCheck) {
@@ -54200,10 +54681,9 @@ class EventSourceStream extends Transform {
         if (this.crlfCheck) {
           // If the current character is a line feed, we can remove it
           // from the buffer and reset the crlfCheck flag
-          if (this.buffer[this.pos] === LF) {
-            this.buffer = this.buffer.subarray(this.pos + 1)
-            this.pos = 0
+          if (byte === LF) {
             this.crlfCheck = false
+            this.consumeCurrentByte()
 
             // It is possible that the line feed is not the end of the
             // event. We need to check if the next character is an
@@ -54219,19 +54699,17 @@ class EventSourceStream extends Transform {
           this.crlfCheck = false
         }
 
-        if (this.buffer[this.pos] === LF || this.buffer[this.pos] === CR) {
+        if (byte === LF || byte === CR) {
           // If the current character is a carriage return, we need to
           // set the crlfCheck flag to true, as we need to check if the
           // next character is a line feed so we can remove it from the
           // buffer
-          if (this.buffer[this.pos] === CR) {
+          if (byte === CR) {
             this.crlfCheck = true
           }
 
-          this.buffer = this.buffer.subarray(this.pos + 1)
-          this.pos = 0
-          if (
-            this.event.data !== undefined || this.event.event || this.event.id !== undefined || this.event.retry) {
+          this.consumeCurrentByte()
+          if (this.hasPendingEvent()) {
             this.processEvent(this.event)
           }
           this.clearEvent()
@@ -54245,22 +54723,18 @@ class EventSourceStream extends Transform {
 
       // If the current character is an end-of-line, we can process the
       // line
-      if (this.buffer[this.pos] === LF || this.buffer[this.pos] === CR) {
+      if (byte === LF || byte === CR) {
         // If the current character is a carriage return, we need to
         // set the crlfCheck flag to true, as we need to check if the
         // next character is a line feed
-        if (this.buffer[this.pos] === CR) {
+        if (byte === CR) {
           this.crlfCheck = true
         }
 
         // In any case, we can process the line as we reached an
         // end-of-line character
-        this.parseLine(this.buffer.subarray(0, this.pos), this.event)
-
-        // Remove the processed line from the buffer
-        this.buffer = this.buffer.subarray(this.pos + 1)
-        // Reset the position as we removed the processed line from the buffer
-        this.pos = 0
+        this.parseLine(this.readLine(), this.event)
+        this.consumeCurrentByte()
         // A line was processed and this could be the end of the event. We need
         // to check if the next line is empty to determine if the event is
         // finished.
@@ -54268,7 +54742,7 @@ class EventSourceStream extends Transform {
         continue
       }
 
-      this.pos++
+      this.advanceCursor()
     }
 
     callback()
@@ -54293,64 +54767,53 @@ class EventSourceStream extends Transform {
       return
     }
 
-    let field = ''
-    let value = ''
+    let fieldLength = line.length
+    let valueStart = line.length
 
     // If the line contains a U+003A COLON character (:)
     if (colonPosition !== -1) {
-      // Collect the characters on the line before the first U+003A COLON
-      // character (:), and let field be that string.
-      // TODO: Investigate if there is a more performant way to extract the
-      // field
-      // see: https://github.com/nodejs/undici/issues/2630
-      field = line.subarray(0, colonPosition).toString('utf8')
+      fieldLength = colonPosition
 
       // Collect the characters on the line after the first U+003A COLON
       // character (:), and let value be that string.
       // If value starts with a U+0020 SPACE character, remove it from value.
-      let valueStart = colonPosition + 1
+      valueStart = colonPosition + 1
       if (line[valueStart] === SPACE) {
         ++valueStart
       }
-      // TODO: Investigate if there is a more performant way to extract the
-      // value
-      // see: https://github.com/nodejs/undici/issues/2630
-      value = line.subarray(valueStart).toString('utf8')
-
-      // Otherwise, the string is not empty but does not contain a U+003A COLON
-      // character (:)
-    } else {
-      // Process the field using the steps described below, using the whole
-      // line as the field name, and the empty string as the field value.
-      field = line.toString('utf8')
-      value = ''
     }
 
-    // Modify the event with the field name and value. The value is also
-    // decoded as UTF-8
-    switch (field) {
-      case 'data':
-        if (event[field] === undefined) {
-          event[field] = value
-        } else {
-          event[field] += `\n${value}`
-        }
-        break
-      case 'retry':
-        if (isASCIINumber(value)) {
-          event[field] = value
-        }
-        break
-      case 'id':
-        if (isValidLastEventId(value)) {
-          event[field] = value
-        }
-        break
-      case 'event':
-        if (value.length > 0) {
-          event[field] = value
-        }
-        break
+    if (isFieldName(line, fieldLength, DATA)) {
+      const value = line.toString('utf8', valueStart)
+
+      if (event.data === undefined) {
+        event.data = value
+      } else {
+        event.data += `\n${value}`
+      }
+      return
+    }
+
+    if (isFieldName(line, fieldLength, RETRY)) {
+      if (isASCIINumberBytes(line, valueStart)) {
+        event.retry = line.toString('utf8', valueStart)
+      }
+      return
+    }
+
+    if (isFieldName(line, fieldLength, ID)) {
+      if (isValidLastEventIdBytes(line, valueStart)) {
+        event.id = line.toString('utf8', valueStart)
+      }
+      return
+    }
+
+    if (isFieldName(line, fieldLength, EVENT)) {
+      const value = line.toString('utf8', valueStart)
+
+      if (value.length > 0) {
+        event.event = value
+      }
     }
   }
 
@@ -54380,13 +54843,152 @@ class EventSourceStream extends Transform {
   }
 
   clearEvent () {
-    this.event = {
-      data: undefined,
-      event: undefined,
-      id: undefined,
-      retry: undefined
+    this.event.data = undefined
+    this.event.event = undefined
+    this.event.id = undefined
+    this.event.retry = undefined
+  }
+
+  hasPendingEvent () {
+    return this.event.data !== undefined ||
+      this.event.event !== undefined ||
+      this.event.id !== undefined ||
+      this.event.retry !== undefined
+  }
+
+  hasCurrentByte () {
+    return this.chunkIndex < this.chunks.length &&
+      this.pos < this.chunks[this.chunkIndex].length
+  }
+
+  currentByte () {
+    return this.chunks[this.chunkIndex][this.pos]
+  }
+
+  consumeCurrentByte () {
+    this.advanceCursor()
+    this.syncLineStartToCursor()
+  }
+
+  advanceCursor () {
+    this.pos++
+
+    while (this.chunkIndex < this.chunks.length && this.pos >= this.chunks[this.chunkIndex].length) {
+      this.chunkIndex++
+      this.pos = 0
     }
   }
+
+  syncLineStartToCursor () {
+    this.lineChunkIndex = this.chunkIndex
+    this.linePos = this.pos
+    this.dropConsumedChunks()
+  }
+
+  dropConsumedChunks () {
+    while (this.lineChunkIndex > 0) {
+      this.chunks.shift()
+      this.lineChunkIndex--
+      this.chunkIndex--
+    }
+
+    if (this.chunkIndex === this.chunks.length) {
+      this.chunks.length = 0
+      this.chunkIndex = 0
+      this.pos = 0
+      this.lineChunkIndex = 0
+      this.linePos = 0
+    }
+  }
+
+  readLine () {
+    if (this.lineChunkIndex === this.chunkIndex) {
+      return this.chunks[this.chunkIndex].subarray(this.linePos, this.pos)
+    }
+
+    const chunks = []
+    let length = 0
+
+    for (let i = this.lineChunkIndex; i <= this.chunkIndex; i++) {
+      const chunk = this.chunks[i]
+      const start = i === this.lineChunkIndex ? this.linePos : 0
+      const end = i === this.chunkIndex ? this.pos : chunk.length
+      const slice = chunk.subarray(start, end)
+      length += slice.length
+      chunks.push(slice)
+    }
+
+    return Buffer.concat(chunks, length)
+  }
+
+  peekBufferedByte (offset) {
+    let chunkIndex = this.lineChunkIndex
+    let pos = this.linePos
+
+    while (chunkIndex < this.chunks.length) {
+      const chunk = this.chunks[chunkIndex]
+      const remaining = chunk.length - pos
+
+      if (offset < remaining) {
+        return chunk[pos + offset]
+      }
+
+      offset -= remaining
+      chunkIndex++
+      pos = 0
+    }
+  }
+
+  discardLeadingBytes (count) {
+    while (count > 0 && this.lineChunkIndex < this.chunks.length) {
+      const chunk = this.chunks[this.lineChunkIndex]
+      const remaining = chunk.length - this.linePos
+
+      if (count < remaining) {
+        this.linePos += count
+        count = 0
+      } else {
+        count -= remaining
+        this.lineChunkIndex++
+        this.linePos = 0
+      }
+    }
+
+    this.chunkIndex = this.lineChunkIndex
+    this.pos = this.linePos
+    this.dropConsumedChunks()
+  }
+
+  handleBOM () {
+    const first = this.peekBufferedByte(0)
+    const second = this.peekBufferedByte(1)
+    const third = this.peekBufferedByte(2)
+
+    if (second === undefined) {
+      if (first === BOM[0]) {
+        return true
+      }
+
+      this.checkBOM = false
+      return true
+    }
+
+    if (third === undefined) {
+      if (first === BOM[0] && second === BOM[1]) {
+        return true
+      }
+
+      this.checkBOM = false
+      return false
+    }
+
+    if (first === BOM[0] && second === BOM[1] && third === BOM[2]) {
+      this.discardLeadingBytes(3)
+    }
+
+    this.checkBOM = false
+    return !this.hasCurrentByte()
+  }
 }
 
 module.exports = {
@@ -65234,13 +65836,13 @@ function establishWebSocketConnection (url, protocols, client, handler, options)
         // The presence of a session property on the socket indicates HTTP2
         // HTTP1
         if (response.socket?.session == null) {
-          failWebsocketConnection(handler, 1002, 'Received network error or non-101 status code.', response.error)
+          failHandshake(handler, response, 1002, 'Received network error or non-101 status code.', response.error)
           return
         }
 
         // HTTP2
         if (response.status !== 200) {
-          failWebsocketConnection(handler, 1002, 'Received network error or non-200 status code.', response.error)
+          failHandshake(handler, response, 1002, 'Received network error or non-200 status code.', response.error)
           return
         }
       }
@@ -65255,7 +65857,7 @@ function establishWebSocketConnection (url, protocols, client, handler, options)
       //    header list results in null, failure, or the empty byte
       //    sequence, then fail the WebSocket connection.
       if (protocols.length !== 0 && !response.headersList.get('Sec-WebSocket-Protocol')) {
-        failWebsocketConnection(handler, 1002, 'Server did not respond with sent protocols.')
+        failHandshake(handler, response, 1002, 'Server did not respond with sent protocols.')
         return
       }
 
@@ -65271,7 +65873,7 @@ function establishWebSocketConnection (url, protocols, client, handler, options)
       //    _Fail the WebSocket Connection_.
       //    For H2, no upgrade header is expected.
       if (response.socket.session == null && response.headersList.get('Upgrade')?.toLowerCase() !== 'websocket') {
-        failWebsocketConnection(handler, 1002, 'Server did not set Upgrade header to "websocket".')
+        failHandshake(handler, response, 1002, 'Server did not set Upgrade header to "websocket".')
         return
       }
 
@@ -65281,7 +65883,7 @@ function establishWebSocketConnection (url, protocols, client, handler, options)
       //    MUST _Fail the WebSocket Connection_.
       //    For H2, no connection header is expected.
       if (response.socket.session == null && response.headersList.get('Connection')?.toLowerCase() !== 'upgrade') {
-        failWebsocketConnection(handler, 1002, 'Server did not set Connection header to "upgrade".')
+        failHandshake(handler, response, 1002, 'Server did not set Connection header to "upgrade".')
         return
       }
 
@@ -65295,7 +65897,7 @@ function establishWebSocketConnection (url, protocols, client, handler, options)
       const secWSAccept = response.headersList.get('Sec-WebSocket-Accept')
       const digest = crypto.hash('sha1', keyValue + uid, 'base64')
       if (secWSAccept !== digest) {
-        failWebsocketConnection(handler, 1002, 'Incorrect hash received in Sec-WebSocket-Accept header.')
+        failHandshake(handler, response, 1002, 'Incorrect hash received in Sec-WebSocket-Accept header.')
         return
       }
 
@@ -65313,7 +65915,7 @@ function establishWebSocketConnection (url, protocols, client, handler, options)
         extensions = parseExtensions(secExtension)
 
         if (!extensions.has('permessage-deflate')) {
-          failWebsocketConnection(handler, 1002, 'Sec-WebSocket-Extensions header does not match.')
+          failHandshake(handler, response, 1002, 'Sec-WebSocket-Extensions header does not match.')
           return
         }
       }
@@ -65333,8 +65935,8 @@ function establishWebSocketConnection (url, protocols, client, handler, options)
         // is specified, the server needs to include the same field and one of
         // the selected subprotocol values in its response for the connection to
         // be established.
-        if (!requestProtocols.includes(secProtocol)) {
-          failWebsocketConnection(handler, 1002, 'Protocol was not set in the opening handshake.')
+        if (requestProtocols === null || !requestProtocols.includes(secProtocol)) {
+          failHandshake(handler, response, 1002, 'Protocol was not set in the opening handshake.')
           return
         }
       }
@@ -65429,6 +66031,16 @@ function closeWebSocketConnection (object, code, reason, validate = false) {
   }
 }
 
+function failHandshake (handler, response, code, reason, cause) {
+  // The H2 upgrade request has already completed and handed off its stream.
+  // Aborting the request cannot close that stream after handshake validation fails.
+  if (response.socket?.session != null && !response.socket.destroyed) {
+    response.socket.destroy()
+  }
+
+  failWebsocketConnection(handler, code, reason, cause)
+}
+
 /**
  * @param {import('./websocket').Handler} handler
  * @param {number} code
@@ -66147,7 +66759,12 @@ class PerMessageDeflate {
 
         if (this.#maxPayloadSize > 0 && this.#inflate[kLength] > this.#maxPayloadSize) {
           callback(new MessageSizeExceededError())
+          // The inflater may still hold buffered input that can emit a late
+          // zlib error. Remove the data listener, then deterministically stop
+          // the stream so a subsequent 'error' cannot fire without a listener
+          // (which would terminate the process as an unhandled error event).
           this.#inflate.removeAllListeners()
+          this.#inflate.destroy()
           this.#inflate = null
           return
         }
@@ -66970,9 +67587,9 @@ class WebSocketStream {
   /** @type {ReadableStreamDefaultController} */
   #readableStreamController
 
-  // Each WebSocketStream object has an associated writable stream , which is a WritableStream .
-  /** @type {WritableStream} */
-  #writableStream
+  // Retain the controller so the writable stream can be errored while locked.
+  /** @type {WritableStreamDefaultController} */
+  #writableStreamController
 
   // Each WebSocketStream object has an associated boolean handshake aborted , which is initially false.
   #handshakeAborted = false
@@ -67236,6 +67853,9 @@ class WebSocketStream {
     // 12. Let writable be a new WritableStream .
     // 13. Set up writable with writeAlgorithm , closeAlgorithm , and abortAlgorithm .
     const writable = new WritableStream({
+      start: (controller) => {
+        this.#writableStreamController = controller
+      },
       write: (chunk) => this.#write(chunk),
       close: () => closeWebSocketConnection(this.#handler, null, null),
       abort: (reason) => this.#closeUsingReason(reason)
@@ -67244,9 +67864,6 @@ class WebSocketStream {
     // Set stream ’s readable stream to readable .
     this.#readableStream = readable
 
-    // Set stream ’s writable stream to writable .
-    this.#writableStream = writable
-
     // Resolve stream ’s opened promise with WebSocketOpenInfo «[ " extensions " → extensions , " protocol " → protocol , " readable " → readable , " writable " → writable ]».
     this.#openedPromise.resolve({
       extensions,
@@ -67332,9 +67949,7 @@ class WebSocketStream {
       this.#readableStreamController.close()
 
       // 6.2. Error stream ’s writable stream with an " InvalidStateError " DOMException indicating that a closed WebSocketStream cannot be written to.
-      if (!this.#writableStream.locked) {
-        this.#writableStream.abort(new DOMException('A closed WebSocketStream cannot be written to', 'InvalidStateError'))
-      }
+      this.#writableStreamController.error(new DOMException('A closed WebSocketStream cannot be written to', 'InvalidStateError'))
 
       // 6.3. Resolve stream ’s closed promise with WebSocketCloseInfo «[ " closeCode " → code , " reason " → reason ]».
       this.#closedPromise.resolve({
@@ -67351,7 +67966,7 @@ class WebSocketStream {
       this.#readableStreamController?.error(error)
 
       // 7.3. Error stream ’s writable stream with error .
-      this.#writableStream?.abort(error)
+      this.#writableStreamController?.error(error)
 
       // 7.4. Reject stream ’s closed promise with error .
       this.#closedPromise.reject(error)
diff --git a/package-lock.json b/package-lock.json
index 22b2ed6..5314a58 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -4233,9 +4233,9 @@
       }
     },
     "node_modules/undici": {
-      "version": "7.29.0",
-      "resolved": "https://registry.npmjs.org/undici/-/undici-7.29.0.tgz",
-      "integrity": "sha512-IDxfleLmmbSskfWSUATiN1nfn2rDuvnMOqb5CWR92iIfojA0Ud+ulOAAEQ57LPr9rWmsreUyf5lwyao+7GNNVw==",
+      "version": "7.30.0",
+      "resolved": "https://registry.npmjs.org/undici/-/undici-7.30.0.tgz",
+      "integrity": "sha512-dkrQXeHSaoamnItlYbmzG0wFYrM0ZwDxCIg0A7aKjTyyhh9svRzCNFEzV+Vm05/yehjCzjDZ31KXfGEjYSztDQ==",
       "license": "MIT",
       "engines": {
         "node": ">=20.18.1"