CVE-2026-44511: Katalyst Koi

High severity, CVSS 7.4. EPSS: 0.3% chance of exploitation in the next 30 days.

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.

Affected products

• Katalyst Koi: before 4.20.0 (fixed in 4.20.0); from 5.0.0, up to and including 5.6.0

Published 2026-05-14. Last modified 2026-06-17.