Description
GitLab has remediated an issue in GitLab CE/EE affecting all versions from 11.2 before 18.9.6, 18.10 before 18.10.4, and 18.11 before 18.11.1 that under certain conditions could have allowed an authenticated user with project owner permissions to bypass group fork prevention settings due to improper authorization checks.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| GitLab | GitLab | 11.2 – < 18.9.6, 18.10 – < 18.10.4, 18.11 – < 18.11.1 | 18.9.6 |
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
- NCSC-2026-0128 Kwetsbaarheden verholpen in GitLab EE en CE NCSC-NL (Netherlands) · Apr 23, 2026
- WID-SEC-2026-1245 GitLab: Mehrere Schwachstellen BSI CERT-Bund (WID) · Apr 22, 2026
References
- HackerOne Bug Bounty Report #3275222 technical-description exploit permissions-required
- https://gitlab.com/gitlab-org/gitlab/-/work_items/567781
- https://about.gitlab.com/releases/2026/04/22/patch-release-gitlab-18-11-1-released/