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OpenAdvisories
Medium · 4.2 CVE-2026-126076 EUVD-2026-122925GHSA-2586-8ghr-69fj

Action Pack: Possible restoration of destroyed sessions in Action Dispatch CacheStore

Published Nov 10, 2026 · Updated Nov 12, 2026 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
rails rails >= 8.1, < 8.1.4.1, < 8.0.5.2 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 rails No fix yet —
Debian 13 rails No fix yet —
Debian 12 rails No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 rails No fix yet —
Ubuntu 26.04 LTS rails No fix yet —
Ubuntu 24.04 LTS rails No fix yet —
Show 4 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 22.04 LTS rails No fix yet —
Ubuntu Pro 20.04 LTS rails No fix yet —
Ubuntu Pro 18.04 LTS rails No fix yet —
Ubuntu Pro 16.04 LTS rails No fix yet —

Affected packages

EcosystemPackageAffectedFixedRecord
RubyGems actionpack >= 8.1.0.beta1, < 8.1.4.1 8.1.4.1 GHSA-2586-8ghr-69fj
RubyGems actionpack < 8.0.5.2 8.0.5.2 GHSA-2586-8ghr-69fj

Advisories 1

References