Description
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.
Affected products
gitlab: gitlab
References3
- about.gitlab.com/releases/2026/05/13/patch-release-gitlab-18-11… Release Notes
- gitlab.com/gitlab-org/gitlab/-/work_items/596760 Broken Link
- hackerone.com/reports/3673647 Permissions Required
Metrics
- CVSS 3.1
-
5.4
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 9 · as of 14 November 2026
- CWE
- CWE-79
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.