[ CVE-2026-84933 · Published 4 Sep 2026 ]
undici vulnerable to cross-user cookie disclosure via Set-Cookie caching in shared caches
[ Description ]Official description
undici's cache interceptor does not handle the Set-Cookie response header anywhere in its cache path, so it neither refuses to store nor strips that header. In shared cache mode, which is the default, an otherwise cacheable response that carries a Set-Cookie header, for example one marked with a public and max-age directive, is stored and then re-served to a later caller that matches the same cache key. As a result one caller's cookie is disclosed to a different caller, and an untrusted server can inject cookies into cached responses served to all subsequent callers. This violates the requirement that a shared cache must not store cookies. This affects undici versions from 7.0.0 up to 7.29.1 and from 8.0.0 up to 8.10.2. Users should upgrade to undici 7.29.1 or 8.10.2.
[ Fixes ]Fixes and patches
- undici 7.29.1Fixed version · GitHub Advisories · npm package undici: upgrade to 7.29.1 or later (affected >= 7.0.0, < 7.29.1)
- undici 8.10.2Fixed version · GitHub Advisories · npm package undici: upgrade to 8.10.2 or later (affected >= 8.0.0, < 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 >= 7.0.0, < 7.29.1 · fixed in 7.29.1 · GHSA-2jfj-6hjv-fm6j
- undici npmAffected >= 8.0.0, < 8.10.2 · fixed in 8.10.2 · GHSA-2jfj-6hjv-fm6j