Vulnerability in GitLab
CVE-2025-8405
GitLab has remediated a security issue in GitLab CE/EE affecting all versions from 17.1 before 18.4.6, 18.5 before 18.5.4, and 18.6 before 18.6.2 that could have allowed an authenticated user to perform unauthorized actions on behalf of other users by injecting malicious HTML into vulnerability code flow displays.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.005 (41.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 41.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: +0.000
Affected products
- GitLab — versions 17.1, 18.5, 18.6
Weakness classification (CWE)
References
- gitlab.com/gitlab-org/gitlab/-/issues/558214 (issue-tracking, permissions-required, Broken Link)
- hackerone.com/reports/3270940 (Permissions Required, technical-description, permissions-required, exploit)
- about.gitlab.com/releases/2025/12/10/patch-release-gitlab-18-6-2-released/ (Release Notes, Vendor Advisory)
Frequently asked questions
- What is CVE-2025-8405?
- CVE-2025-8405 is a high-severity vulnerability in GitLab, classified under Improper Encoding or Escaping of Output. CVSS score: 7.7/10. Published 2025-12-11.
- How severe is CVE-2025-8405?
- High severity. CVSS v3 base score is 7.7 out of 10.