GitLab CE/EE Stored Cross-Site Scripting Vulnerability in GitLab Flavored Markdown

A stored cross-site scripting vulnerability has been identified in GitLab Community Edition (CE) and Enterprise Edition (EE) versions 18.2.2 prior to 18.5.5, 18.6 prior to 18.6.3, and 18.7 prior to 18.7.1. This vulnerability could have allowed an authenticated user to inject malicious scripts by exploiting the way GitLab Flavored Markdown processed placeholders.

Impact

Exploitation of this vulnerability allowed for stored cross-site scripting, where injected scripts would be executed in the context of the user.

Remediation

Users are advised to upgrade to GitLab versions 18.7.1, 18.6.3, or 18.5.5. Instructions for updating GitLab can be found on the GitLab Update page. For GitLab Runner, refer to the Updating the Runner page.