CVE-2026-126077

NameCVE-2026-126077
DescriptionAction Pack is a framework for handling and responding to web requests. Prior to 8.1.4.1 and 8.0.5.2, When ActionDispatch::Cookies reads a signed or encrypted cookie that was written under a rotated secret (config.action_dispatch.cookies_rotations) or in the format that a :hybrid cookie serializer migrates from, it writes the cookie back to the response in the current format, and that write ignores request.session_options[:skip]. ActiveStorage::DisableSession relies on that option to keep the session cookie off the public, immutable responses of the Active Storage proxy controllers, but those controllers still load the session, so a request carrying an old-format session cookie could receive the rewritten session cookie in Set-Cookie on a cacheable response. A shared cache that stores such a response together with its Set-Cookie header could then serve one user's session to later requesters of the same URL, or serve an attacker's session to other users. Applications are affected when they serve Active Storage files through the proxy controllers, have a cookie rotation or a :hybrid serializer migration configured, and run behind a cache that stores Set-Cookie on public responses. This is a path around the fix for CVE-2024-26144. This issue is fixed in versions 8.1.4.1 and 8.0.5.2.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
rails (PTS)bookworm2:6.1.7.10+dfsg-1~deb12u2vulnerable
bookworm (security)2:6.1.7.10+dfsg-1~deb12u3vulnerable
trixie2:7.2.2.2+dfsg-2~deb13u1vulnerable
trixie (security)2:7.2.2.2+dfsg-2~deb13u2vulnerable
forky2:7.2.4+dfsg-1vulnerable
sid2:7.2.4+dfsg-2vulnerable

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
railssource(unstable)(unfixed)

Notes

https://github.com/rails/rails/security/advisories/GHSA-x6mj-8jx9-qhqv

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