CVE-2026-85024Medium· 5.9▾ Sunlitundici bundles a WebSocket client whose permessage-deflate size-limit cleanup removes all listeners from the internal zlib inflate stream, including its error listener, while that stream can still emit. When a remote peer sends a compres…
▾ Sunlit zone — Low / medium · no exploitation signal
impact 32.5 · likelihood 0.1 · exploitation 0
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Exploit-prediction probability, daily snapshots since Sep 8.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
0.3%
Last analysed / modified upstream
0.3% → 0.4%
undici bundles a WebSocket client whose permessage-deflate size-limit cleanup removes all listeners from the internal zlib inflate stream, including its error listener, while that stream can still emit. When a remote peer sends a compressed payload that crosses the built-in 128 MiB decompressed-payload limit and then contains a malformed DEFLATE byte, the inflate stream emits a data error with no listener attached, which Node.js treats as a fatal unhandled error and terminates the entire process. Exploitation is remote and unauthenticated, requires no application mistake, and is asymmetric, since roughly 130 KB on the wire expands past the limit and crashes the process, and reconnecting can repeat the crash. This affects undici versions from 6.25.0 up to 6.28.1, from 7.28.0 up to 7.29.1, and from 8.1.0 up to 8.10.2. Users should upgrade to undici 6.28.1, 7.29.1, or 8.10.2.
undici >= 6.25.0, < 6.28.1undici >= 7.28.0, < 7.29.1undici >= 8.1.0, < 8.10.2Upgrade past the affected range:
undici 8.10.2Affected packages:
undici >= 6.25.0, < 6.28.1undici >= 7.28.0, < 7.29.1undici >= 8.1.0, < 8.10.2Patched in:
undici 6.28.1undici 7.29.1undici 8.10.2Connected by shared product, vendor, weakness, or advisory.
CVE-2026-19534High· 7.5undici's WebSocket client crashes the whole Node.js process during the opening handshake when a server responds with a subprotocol that the client never requested
CVE-2026-84947Low· 3.7undici's dump interceptor reads and discards a response body up to a configurable maximum size
CVE-2026-85014Medium· 5.9undici's experimental WebSocketStream client crashes the whole Node.js process when a remote peer closes the TCP connection without a WebSocket close handshake
CVE-2026-84890Medium· 5.9undici's decompress interceptor decompresses response bodies according to the untrusted Content-Encoding header
CVE-2026-18149Medium· 5.9undici's retry handler can leave an already-exposed response body pending forever
CVE-2026-18540Low· 3.7undici's retry interceptor can append the body of a ranged retry response to bytes already delivered from an earlier partial response while still presenting the original response's status and headers