Summary
GitLab Community Edition and Enterprise Edition contain a integer overflow or wraparound vulnerability that could allow an unauthenticated user to execute arbitrary code on the GitLab server via a specially crafted regular expression in a CI/CD configuration, due to insufficient regular expression validation.
What to do
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Notes and references
Other products can potentially be affected by the same underlying Ruby/Onigmo Integer Overflow issue in CI/CD Regular Expression Compiler. For more information please see: https://www.ruby-lang.org/en/news/2026/10/23/regexp-fixes-for-gitlab-cves ; https://docs.gitlab.com/releases/patches/patch-release-gitlab-19-4-2-released/ ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-97229