Description
Katalyst Koi is a framework for building Rails admin functionality. Prior to 4.20.0 and 5.6.0, admin session cookies were not invalidated when an admin user logged out. An attacker with access to a valid admin session cookie could continue to access admin functionality after logout, until the cookie expired or session secrets were rotated. This vulnerability is fixed in 4.20.0 and 5.6.0.
References1
Metrics
- CVSS 3.1
-
7.4
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - EPSS — exploit probability
- 0% percentile: 10 · as of 14 November 2026
- CWE
- CWE-613
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.