GitLab CE/EE Regular Expression Denial-of-Service Vulnerability in Merge Requests

A regular expression denial-of-service vulnerability has been identified in GitLab Community Edition (CE) and Enterprise Edition (EE) versions 9.2 prior to 18.7.5, 18.8 prior to 18.8.5, and 18.9 prior to 18.9.1. This vulnerability could have allowed an unauthenticated user to disrupt service by sending specially crafted input to a merge request endpoint, under certain conditions.

Impact

Exploitation of this vulnerability could lead to a denial-of-service condition, causing increased resource consumption and potentially degrading the performance of the GitLab instance.

Remediation

Users are strongly recommended to upgrade to GitLab versions 18.9.1, 18.8.5, or 18.7.5. Instructions for updating GitLab can be found on the GitLab Update page.