Description
GitLab has remediated an issue in GitLab CE/EE affecting all versions from 15.11 before 18.9.7, 18.10 before 18.10.6, and 18.11 before 18.11.3 that could have allowed an authenticated user to inject HTML and JavaScript into email notifications sent to other users due to improper input 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/579385 Not Applicable
- hackerone.com/reports/3368096 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: 7 · as of 14 November 2026
- CWE
- CWE-94
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.