CVE-2025-46336: Rack session gets restored after deletion

Severity: medium (CVSS 4.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-05-08 · updated 2026-06-17
Weakness: CWE-362

Description

Rack::Session is a session management implementation for Rack. In versions starting from 2.0.0 to before 2.1.1, when using the Rack::Session::Pool middleware, and provided the attacker can acquire a session cookie (already a major issue), the session may be restored if the attacker can trigger a long running request (within that same session) adjacent to the user logging out, in order to retain illicit access even after a user has attempted to logout. This issue has been patched in version 2.1.1.

Affected products

rack-session: from 2.0.0, < 2.1.1

References

https://github.com/rack/rack-session/commit/c28c4a8c1861d814e09f2ae48264ac4c40be2d3b
https://github.com/rack/rack-session/security/advisories/GHSA-9j94-67jr-4cqj
https://github.com/rack/rack/security/advisories/GHSA-vpfw-47h7-xj4g

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