CVE-2025-12653: GitLab

Medium severity, CVSS 6.5. EPSS: 0.3% chance of exploitation in the next 30 days.

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.3 before 18.4.5, 18.5 before 18.5.3, and 18.6 before 18.6.1 that under specific conditions could have allowed an unauthenticated user to join arbitrary organizations by changing headers on some requests.

Affected products

• GitLab GitLab: from 18.3.0, before 18.4.5 (fixed in 18.4.5); from 18.5.0, before 18.5.3 (fixed in 18.5.3); version 18.6.0 only

Published 2025-11-26. Last modified 2026-06-17.