Vulnerability in GitLab
CVE-2026-3254
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.5 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (15.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 15.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- GitLab — versions 18.11, 18.11.0
Weakness classification (CWE)
References
- hackerone.com/reports/3572752 (Permissions Required, technical-description, permissions-required, exploit)
- gitlab.com/gitlab-org/gitlab/-/work_items/591587 (Broken Link)
Frequently asked questions
- What is CVE-2026-3254?
- CVE-2026-3254 is a low-severity vulnerability in GitLab, classified under Improper Restriction of Rendered UI Layers or Frames (Clickjacking). CVSS score: 3.5/10. Published 2026-04-22.
- How severe is CVE-2026-3254?
- Low severity. CVSS v3 base score is 3.5 out of 10.