Bug 2531876

Summary: CVE-2026-84933 nodejs24: undici: Cross-user cookie disclosure via Set-Cookie caching [fedora-all]
Product: [Fedora] Fedora Reporter: Samuele Negrini <snegrini>
Component: nodejs24Assignee: Jan Staněk <jstanek>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: aradchen, jstanek, tjuhasz
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["f513a701-ad3c-4141-8a58-2b801cbcab86"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:    
Bug Blocks: 2528756    

Description Samuele Negrini 2026-09-11 13:19:43 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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.