Description
GitLab has remediated an issue in GitLab CE/EE affecting all versions from 9.2 before 18.7.5, 18.8 before 18.8.5, and 18.9 before 18.9.1 that could have allowed an unauthenticated user to cause regular expression denial of service by sending specially crafted input to a merge request endpoint under certain conditions.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| GitLab | GitLab | 9.2 – < 18.7.5, 18.8 – < 18.8.5, 18.9 – < 18.9.1 | 18.7.5 |
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-2026-0072 Kwetsbaarheden verholpen in GitLab NCSC-NL (Netherlands) · Feb 27, 2026
- WID-SEC-2026-0529 GitLab: Mehrere Schwachstellen BSI CERT-Bund (WID) · Feb 25, 2026
References
- GitLab Issue #587560 issue-tracking permissions-required
- HackerOne Bug Bounty Report #3482893 technical-description exploit permissions-required
- https://about.gitlab.com/releases/2026/02/25/patch-release-gitlab-18-9-1-released/