Vulnerability · Published May 14, 2026 · Assigned by GitHub_M

CVE-2026-44511Katalyst Koi: Session cookies can be replayed after user logout

High 7.4

In plain English

A high-severity security flaw in koi from katalyst. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 9% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.4High
Exploit odds (30 days)0.2%top 90.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
RubyGemskatalyst-koi4.20.0GHSA-4cx3-3c38-j9vv
RubyGemskatalyst-koi5.6.0GHSA-4cx3-3c38-j9vv

Affected products (as reported)

VendorProductVersions
katalyst koi < 4.20.0>= 5.0.0 <= 5.6.0

Weakness: CWE-613 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

References