Vulnerability in Rack Rack-Session

CVE-2025-46336

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.

Vulnerability class: Race Condition

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (22.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 22.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-46336: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-46336?
CVE-2025-46336 is a medium-severity vulnerability in Rack Rack-Session, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 4.2/10. Published 2025-05-08.
How severe is CVE-2025-46336?
Medium severity. CVSS v3 base score is 4.2 out of 10.