Vulnerability in GitLab
CVE-2025-12653
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (19.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 19th percentile — 19.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- GitLab — versions 18.3, 18.5, 18.6.0
Weakness classification (CWE)
References
- about.gitlab.com/releases/2025/11/26/patch-release-gitlab-18-6-1-released/ (vendor-advisory)
- gitlab.com/gitlab-org/gitlab/-/issues/579372 (issue-tracking, permissions-required, Broken Link)
- hackerone.com/reports/3370245 (Permissions Required, technical-description, permissions-required, exploit)
Frequently asked questions
- What is CVE-2025-12653?
- CVE-2025-12653 is a medium-severity vulnerability in GitLab, classified under Authentication Bypass by Spoofing. CVSS score: 6.5/10. Published 2025-11-26.
- How severe is CVE-2025-12653?
- Medium severity. CVSS v3 base score is 6.5 out of 10.