Vulnerability in katalyst-koi (CVE-2026-44511)
Summary
Vulnerability in katalyst-koi (CVE-2026-44511). Confidential information can be exposed externally. Mitigation: upgrade to 5.6.0 or later.
Original description
The description as published by the source.
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
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-44511 has been found in katalyst-koi.
Confidential information can be exposed externally. CVSS score: 7.4/10.
What to do: upgrade katalyst-koi to 5.6.0 or later.
If unsure, ask your IT team or search "katalyst-koi CVE-2026-44511" on the vendor's site.
CVE-2026-44511 (katalyst-koi) — CWE-613 / CVSS v3 7.4
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 5.6.0 — apply immediately
Workaround: Katalyst Koi recommends upgrading to the latest available version, or back porting the changes released in 5.6.0/4.20.0
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-613) exists in katalyst-koi.
Check the vendor advisory for the affected versions of katalyst-koi.
Severity: High (CVSS 7.4/10). Confidential information can be exposed externally.
Update to 5.6.0.
Workaround: Katalyst Koi recommends upgrading to the latest available version, or back porting the changes released in 5.6.0/4.20.0
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'katalyst-koi' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'katalyst-koi' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
katalyst-koiを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
Katalyst Koi recommends upgrading to the latest available version, or back porting the changes released in 5.6.0/4.20.0パッチが適用されるまでの応急処置として、Katalyst Koi recommends upgrading to the latest available version, or back porting the changes released in 5.6.0/4.20.0 を実施。回避策の副作用 (機能低下) を確認した上で。
-
3Apply patch patch
Upgrade katalyst-koi to 5.6.0ステージング環境で 5.6.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
4Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web guides.rubyonrails.org
- web github.com
- web github.com