Description
GitLab has remediated an issue in GitLab CE/EE affecting all versions from 19.1 before 19.2.8, 19.3 before 19.3.5, and 19.4 before 19.4.2 that, under certain conditions, could have allowed an authenticated user to execute arbitrary JavaScript in the context of other users' browser sessions via a specially crafted repository, due to improper sanitization of HTML attributes in syntax-highlighted output.
Affected products
gitlab: gitlab
References3
- docs.gitlab.com/releases/patches/patch-release-gitlab-19-4-2-re… Release NotesVendor Advisory
- gitlab.com/gitlab-org/gitlab/-/work_items/629523 Issue Tracking
- hackerone.com/reports/3936831 Permissions Required
Metrics
- CVSS 3.1
-
8.7
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N - EPSS — exploit probability
- 0% percentile: 42 · as of 11 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.