Description
GitLab has remediated an issue in GitLab CE/EE affecting all versions from 15.6 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, under certain conditions, render content in dialogs to other users by injecting malicious HTML content into merge request titles.
Affected products
gitlab: gitlab
References3
- about.gitlab.com/releases/2025/12/10/patch-release-gitlab-18-6-… Release NotesVendor Advisory
- gitlab.com/gitlab-org/gitlab/-/issues/579573 Broken Link
- hackerone.com/reports/3379381 Permissions Required
Metrics
- CVSS 3.1
-
3.5
LOW
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N - EPSS — exploit probability
- 0% percentile: 22 · as of 11 November 2026
- CWE
- CWE-116
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.