CVE-2026-3254: GitLab

Low severity, CVSS 3.5. EPSS: 0.3% chance of exploitation in the next 30 days.

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.11 before 18.11.1 that under certain conditions could have allowed an authenticated user to load unauthorized content into another user's browser due to improper input validation in the Mermaid sandbox.

Affected products

• GitLab GitLab: version 18.11.0 only

Published 2026-04-22. Last modified 2026-06-17.