MediumGHSA-rx4f-c7p8-82vqCVE-2026-8501429 Sep · 24 days ago
undici vulnerable to Denial of Service via WebSocketStream unclean close.
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Impact undici's WebSocketStream crashes the client process when a WebSocket connection is closed abruptly without a close handshake. On such an unclean close, the internal socket-close handler calls abort() on the writable stream even when the application holds a writer lock. Per the WHATWG Streams standard, aborting a locked stream returns a promise that rejects with a TypeError , and the handler discards that promise. The unobserved rejection surfaces as an unhandledRejection and, under Node.js's default behavior, terminates the process. A malicious or compromised WebSocket server can crash
SourcesGitHub advisory database
Timeline
29 Sep24 daysfrom publication to Patchwire
- Published by GitHub advisory database29 Sep
- Seen by Patchwire23 Oct
- Fix released29 Sep
undici7.29.18.10.2
Versions of undici
8.x
safe 8.10.2
7.x
safe 7.29.1
AffectedSafe
Related alerts(8)
Same packagesExploitable only if · read by Claude, the source remains the reference
- Project uses undici 6.x before 6.29.1, 7.x before 7.30.1, or 8.x before 8.12.2.
- Application calls undici's fetch() against servers that may be attacker-controlled or malicious.
- The server responds with more than five content codings and closes the connection before sending the body.
- Affected
- undici >=6.23.0 <6.29.1 · undici >=7.18.0 <7.30.1 · undici >=8.0.0 <8.12.2
- Fixed in
- 6.29.1 · 7.30.1 · 8.12.2
- ID
- GHSA-xjj6-f33q-929c
Exploitable only if · read by Claude, the source remains the reference
- Project uses undici's EventSource client.
- undici version is below 6.29.1, 7.30.1, or 8.12.2 in the respective major line.
- The application maintains an EventSource connection to an untrusted or potentially compromised Server-Sent Events peer that controls the response.
- Affected
- undici >=6.5.0 <6.29.1 · undici >=7.0.0 <7.30.1 · undici >=8.0.0 <8.12.2
- Fixed in
- 6.29.1 · 7.30.1 · 8.12.2
- ID
- GHSA-4qv8-2p9j-2685
Exploitable only if · read by Claude, the source remains the reference
- Project uses undici at version 7.15.0 or later, below the patched releases 7.30.1 / 8.12.2.
- Application calls undici's fetch() with Subresource Integrity (integrity) metadata.
- The integrity metadata uses an uppercase or mixed-case algorithm token (e.g. SHA256- or Sha256-).
- An attacker can control the response body returned by the server.
- Affected
- undici >=7.15.0 <7.30.1 · undici >=8.0.0 <8.12.2
- Fixed in
- 7.30.1 · 8.12.2
- ID
- GHSA-f72v-6w45-q472
Exploitable only if · read by Claude, the source remains the reference
- undici version is 7.x before 7.30.1 or 8.x before 8.12.2.
- An originless Agent dispatcher is used (not an origin-bound Client or Pool).
- Interceptors are composed as compose(redirect(), cache()) (not compose(cache(), redirect())).
- The cache interceptor uses a shared cache (type: 'shared') backed by a MemoryCacheStore or SqliteCacheStore.
- Requests can follow redirects whose targets can be attacker-controlled or user-specific (e.g. cross-origin or private/no-store redirects).
- Affected
- undici >=7.0.0 <7.30.1 · undici >=8.0.0 <8.12.2
- Fixed in
- 7.30.1 · 8.12.2
- ID
- GHSA-4w7w-5xrc-9h26
Exploitable only if · read by Claude, the source remains the reference
- Project uses undici at a version before 6.29.1, 7.30.1, or 8.12.2.
- Requests are made through undici's Agent (including as default dispatcher for request, fetch, setGlobalDispatcher) or EnvHttpProxyAgent on direct/NO_PROXY routes.
- The Agent is constructed with a function-valued tls option, such as a custom checkServerIdentity callback for certificate or public-key pinning.
- The TLS options are passed via the tls option rather than via connect.
- Affected
- undici >=4.0.0 <6.29.1 · undici >=7.0.0 <7.30.1 · undici >=8.0.0 <8.12.2
- Fixed in
- 6.29.1 · 7.30.1 · 8.12.2
- ID
- GHSA-2m5v-pch6-74hx
Exploitable only if · read by Claude, the source remains the reference
- Project uses undici (directly or via Node.js global fetch()) at a version before 6.29.1, 7.30.1, or 8.12.2.
- The client makes HTTPS requests to an endpoint that is malicious or compromised.
- The connection to that endpoint negotiates TLS 1.2 (not restricted to TLS 1.3).
- The server initiates renegotiation after the connection is established and presents a different CA-trusted certificate whose hostname does not match the requested host.
- Affected
- undici >=4.2.1 <6.29.1 · undici >=7.0.0 <7.30.1 · undici >=8.0.0 <8.12.2
- Fixed in
- 6.29.1 · 7.30.1 · 8.12.2
- ID
- GHSA-qrxm-fqhp-jwvm
Exploitable only if · read by Claude, the source remains the reference
- Project uses undici's WebSocket client (directly or via Node.js's bundled globalThis.WebSocket).
- Installed undici version is 5.15.0 or later in the 5.x line, or a 6.x, 7.x, or 8.x release earlier than 6.29.1, 7.30.1, or 8.12.2 respectively.
- The client connects to a WebSocket server that is malicious or compromised and can stream PING frames without reading PONG responses.
- Affected
- undici >=5.15.0 <6.29.1 · undici >=7.0.0 <7.30.1 · undici >=8.0.0 <8.12.2
- Fixed in
- 6.29.1 · 7.30.1 · 8.12.2
- ID
- GHSA-9fm3-97px-rjf6
Exploitable only if · read by Claude, the source remains the reference
- Project uses undici at a version before 7.30.1 (7.x) or before 8.12.2 (8.x).
- The client composes undici's decompress interceptor with a downstream response handler that throws during response processing (e.g. the dump interceptor with maxSize).
- The client makes requests to an HTTP server that may be malicious or compromised and can return a compressed body that decompresses beyond the configured limit.
- Affected
- undici >=7.15.0 <7.30.1 · undici >=8.0.0 <8.12.2
- Fixed in
- 7.30.1 · 8.12.2
- ID
- GHSA-55wc-3pg8-jfw6