(rapid7.com) Critical Arbitrary Code Execution Vulnerability in GitLab CI/CD Regular Expression Compiler (CVE-2026-97229)
In brief - This article discusses a critical remote code execution vulnerability (CVE-2026-97229) in GitLab CE and EE, urging self-managed instance administrators to apply urgent patches.
Technically - This article describes an integer overflow (CWE-190) within the CI/CD regular expression compiler of the Ruby Onigmo engine. The vulnerability is triggered when a specially crafted regular expression, initially validated in US-ASCII, is recompiled for UTF-8 encoding against a specific repository path. This overflow leads to the generation of invalid instructions and a loss of control-flow integrity, allowing an attacker to execute arbitrary OS commands as the GitLab git user. Successful exploitation requires the ability to commit a malicious .gitlab-ci.yml file and a UTF-8 repository path to a public project.