GitLab CE/EE Webhook Custom Header Denial-of-Service Vulnerability

A denial-of-service vulnerability has been addressed in GitLab Community Edition (CE) and Enterprise Edition (EE) versions 16.11 prior to 18.7.6, 18.8 prior to 18.8.6, and 18.9 prior to 18.9.2. The issue allowed an authenticated user to cause a denial-of-service condition by exploiting improper input validation on webhook custom header names under certain conditions.

Impact

Exploitation of this vulnerability could lead to a denial-of-service condition, causing disruptions in service availability.

Remediation

Users are strongly advised to upgrade to GitLab versions 18.9.2, 18.8.6, or 18.7.6. Instructions for updating GitLab can be found on the GitLab Update page. For GitLab Runner, refer to the Updating the Runner page.