7.4
High
katalyst-koi

CVE-2026-44511

CVE-2026-44511 is a high-severity security vulnerability in katalyst-koi (rubygems), affecting versions < 4.20.0. It is fixed in 4.20.0, 5.6.0.

Key facts
CVSS score
7.4
High
Attack vector
Network
Issuing authority
GitHub Advisory Database
Affected package
katalyst-koi
Fixed in
4.20.0, 5.6.0
Disclosed
2026

Summary

Impact 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 affects applications using Koi admin authentication where an admin session cookie may have been exposed, cached, intercepted, or otherwise retained after logout. Patches The issue has been patched by recording admin logout time and rejecting any admin session cookie created before the user’s most recent logout. Users should upgrade to the patched Koi releases once available. Workarounds Katalyst Koi recommends upgrading to the latest available version, or back porting the changes released in 5.6.0/4.20.0 Resources This is an application of https://guides.rubyonrails.org/v5.2.0/security.html#replay-attacks-for-cookiestore-sessions

Impact

Severity and exposure

CVE-2026-44511 has a CVSS score of 7.4 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.

A fixed version is available (4.20.0, 5.6.0). Upgrading removes the vulnerable code path.

Affected versions

rubygems

  • katalyst-koi (< 4.20.0)
  • katalyst-koi (>= 5.0.0, < 5.6.0)

Security releases

  • katalyst-koi → 4.20.0 (rubygems)
  • katalyst-koi → 5.6.0 (rubygems)
Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.

Kodem's runtime-powered SCA identifies whether CVE-2026-44511 is reachable in your applications. Explore open-source security for your team.

See if CVE-2026-44511 is reachable in your applications. Get a demo

Remediation advice

Upgrade the following packages to resolve this vulnerability:

  • Upgrade katalyst-koi to 4.20.0 or later
  • Upgrade katalyst-koi to 5.6.0 or later

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently asked questions about CVE-2026-44511

What is CVE-2026-44511?

CVE-2026-44511 is a high-severity security vulnerability in katalyst-koi (rubygems), affecting versions < 4.20.0. It is fixed in 4.20.0, 5.6.0.

How severe is CVE-2026-44511?

CVE-2026-44511 has a CVSS score of 7.4 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which versions of katalyst-koi are affected by CVE-2026-44511?

katalyst-koi (rubygems) versions < 4.20.0 is affected.

Is there a fix for CVE-2026-44511?

Yes. CVE-2026-44511 is fixed in 4.20.0, 5.6.0. Upgrade to this version or later.

Is CVE-2026-44511 exploitable, and should I be worried?

Whether CVE-2026-44511 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo

What actually determines whether CVE-2026-44511 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2026-44511?
  • Upgrade katalyst-koi to 4.20.0 or later
  • Upgrade katalyst-koi to 5.6.0 or later

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