Open-Source Security Intelligence

Know every vulnerability
before it knows you.

DevGuard continuously monitors your dependencies and alerts you when CVEs like this one affect your stack — with real-time threat intelligence built for developers.

Search

GHSA-2586-8ghr-69fj

MediumCVSS 4.2 / 10
Published Nov 10, 2026·Last modified Nov 10, 2026
Affected Components(520)
RubyGems logoactionpack
4.0.1
RubyGems logoactionpack
4.2.6
RubyGems logoactionpack
5.0.7.1
1 / 174
Description

Impact

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.

Details

The fixed releases record which session a request loaded and skip the write when that session's cache entry no longer exists. Changes that such a request makes to the destroyed session are discarded, and Rack logs a warning that the session could not be saved. Each request that writes back a session it loaded makes one additional cache read.

Releases

The fixed releases are available at the normal locations.

Patches for those who cannot upgrade at once:

  • 8.1: https://github.com/rails/rails/commit/d479192cf88a8b30a335a8bc25188a2d8e0f8d9f.patch
  • 8.0: https://github.com/rails/rails/commit/5bb5ec66ed8faaf590ffe1222d7a5eb6e9d050f5.patch

Credit

Found by the team during internal code review.

Upload your SBOM

Upload your own SBOM in CycloneDX 1.6 or higher (JSON) directly here to check your vulnerabilities.

Risk Scores
Base Score
4.2

The vulnerability can be exploited over the network without needing physical access. It is difficult for an attacker to exploit this vulnerability and may require special conditions. An attacker needs basic access or low-level privileges. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a low impact on the confidentiality of the information. There is a low impact on the integrity of the data.

Threat Intelligence
3.9

Limited exploitation activity has been observed. Close monitoring and planned remediation are recommended.

EPSS
0.31%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

Browse More

Scan your project

Continuously monitor your dependencies and get alerted when vulnerabilities like this one affect your stack.

Checkout DevGuard