CVE-2026-126076

Action Pack is a framework for handling and responding to web requests. Prior to 8.1.4.1 and 8.0.5.2, ActionDispatch::Session::CacheStore writes a session back to the cache at the end of each request that loaded it, without checking that the session's cache entry still exists. When a concurrent request destroys the session, through reset_session on logout or by deleting its cache entry on the server, a request that loaded the session earlier and finishes later restores it under its original session ID. Logout and server-side revocation could therefore fail to end a session, and an attacker who holds a stolen session cookie could keep that session valid across the victim's logout. Applications that use config.session_store :cache_store are affected, with any cache backend. ActionDispatch::Session::CookieStore is not affected, nor is ActionDispatch::Session::MemCacheStore with Dalli 4.0.0 or later, whose session store does not write back a session that was deleted. This issue is fixed in versions 8.1.4.1 and 8.0.5.2.

• CWE-613

• https://github.com/rails/rails/commit/5bb5ec66ed8faaf590ffe1222d7a5eb6e9d050f5
• https://github.com/rails/rails/commit/d479192cf88a8b30a335a8bc25188a2d8e0f8d9f
• https://github.com/rails/rails/releases/tag/v8.0.5.2
• https://github.com/rails/rails/releases/tag/v8.1.4.1
• https://github.com/rails/rails/security/advisories/GHSA-2586-8ghr-69fj

Published

Nov 10, 2026

Last Modified

Nov 12, 2026

Status

Awaiting Analysis

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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• CVE-2026-126082Rejected reason: This CVE is a duplicate of another CVE.