XSS in GitLab
CVE-2026-6335
GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.11 before 18.11.3 that under certain conditions could have allowed an authenticated user to execute arbitrary code in another user's browser session due to improper sanitization.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (24.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 24th percentile — 24.4% 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
Weakness classification (CWE)
References
- gitlab.com/gitlab-org/gitlab/-/work_items/596760 (Broken Link)
- hackerone.com/reports/3673647 (Permissions Required, technical-description, permissions-required, exploit)
- about.gitlab.com/releases/2026/05/13/patch-release-gitlab-18-11-3-released/ (Release Notes)
Frequently asked questions
- What is CVE-2026-6335?
- CVE-2026-6335 is a medium-severity vulnerability in GitLab, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-05-14.
- How severe is CVE-2026-6335?
- Medium severity. CVSS v3 base score is 5.4 out of 10.