[ CVE-2026-85024 · Published 4 Sep 2026 ]
undici vulnerable to Denial of Service via unhandled error in WebSocket permessage-deflate decompression
[ Description ]Official description
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.
[ Fixes ]Fixes and patches
- undici 6.28.1Fixed version · GitHub Advisories · npm package undici: upgrade to 6.28.1 or later (affected >= 6.25.0, < 6.28.1)
- undici 7.29.1Fixed version · GitHub Advisories · npm package undici: upgrade to 7.29.1 or later (affected >= 7.28.0, < 7.29.1)
- undici 8.10.2Fixed version · GitHub Advisories · npm package undici: upgrade to 8.10.2 or later (affected >= 8.1.0, < 8.10.2)
[ Advisories ]Government CERT advisories
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CERT-FRCERTFR-2026-AVI-1336
Multiple vulnerabilities in IBM products Translated from French
Multiple vulnerabilities have been discovered in IBM products. Some of them allow an attacker to cause remote arbitrary code execution, privilege escalation and remote denial of service.
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BSI CERT-BundWID-SEC-2026-3596
IBM App Connect Enterprise: Multiple vulnerabilities Translated from German
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CERT-FRCERTFR-2026-AVI-1233
Multiple vulnerabilities in IBM products Translated from French
Multiple vulnerabilities have been discovered in IBM products. Some of them allow an attacker to cause remote arbitrary code execution, remote denial of service and a breach of data confidentiality.
[ Packages ]Affected open-source packages
- undici npmAffected >= 6.25.0, < 6.28.1 · fixed in 6.28.1 · GHSA-3wwx-pv8p-q78v
- undici npmAffected >= 7.28.0, < 7.29.1 · fixed in 7.29.1 · GHSA-3wwx-pv8p-q78v
- undici npmAffected >= 8.1.0, < 8.10.2 · fixed in 8.10.2 · GHSA-3wwx-pv8p-q78v