Description
An issue has been discovered in GitLab CE/EE affecting all versions from 17.6 before 18.3.6, 18.4 before 18.4.4, and 18.5 before 18.5.2, that, under specific conditions, could have allowed unauthorized users to view confidential branch names by accessing project issues with related merge requests.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| GitLab | GitLab | 17.6 – < 18.3.6, 18.4 – < 18.4.4, 18.5 – < 18.5.2 | 18.3.6 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | gitlab | No fix yet | — |
Advisories 2
- WID-SEC-2025-2587 GitLab: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jan 14, 2026
- NCSC-2025-0367 Kwetsbaarheden verholpen in GitLab NCSC-NL (Netherlands) · Nov 18, 2025
References
- https://about.gitlab.com/releases/2025/11/12/patch-release-gitlab-18-5-2-released/
- GitLab Issue #553129 issue-tracking permissions-required
- HackerOne Bug Bounty Report #3214025 technical-description exploit permissions-required