CVE-2026-126076
Received
Received - Intake
Session Fixation in Action Pack Framework
Vulnerability report for CVE-2026-126076, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-11-10
Last updated on: 2026-11-10
Assigner: GitHub, Inc.
Description
Description
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.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
Currently, no data is known.
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-613 | According to WASC, "Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization." |
