CVE-2026-1388
HIGH 7.5 ALL-YEARSGitLab 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.
Severe if exploited (CVSS 7.5), but no confirmed exploitation. Patch on a normal cadence.
Exploitation likelihood
0.4%chance of exploitation in 30 days · 35th percentile
Impact if exploited
7.5CVSS 3.1 · HIGH · CNA
- ConfidentialityNone
- IntegrityNone
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
Search for new PoCs
Search GitHub now — results may be empty or unverified.
Tracked sources are checked weekly for the full archive, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.
Data snapshot:
Weakness (CWE)
- CWE-1333: : Inefficient Regular Expression Complexity
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References and research data (JSON)
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Gitlab | Gitlab | ≥ 9.2.0 and < 18.7.5 |
| Gitlab | Gitlab | ≥ 9.2.0 and < 18.7.5 |
| Gitlab | Gitlab | ≥ 18.8.0 and < 18.8.5 |
| Gitlab | Gitlab | ≥ 18.8.0 and < 18.8.5 |
| Gitlab | Gitlab | 18.9.0 |
| Gitlab | Gitlab | 18.9.0 |
All CVSS metrics
- HIGH 7.5 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - HIGH 7.5 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
Exploit-tagged references (not proof of a PoC)
- https://hackerone.com/reports/3482893 CVE record · GitLab · Updated 2026-02-25T20:05:05.289Z
NVD · CVE-2026-1388 · Updated 2026-06-17T10:15:41.497
Advisories
- https://about.gitlab.com/releases/2026/02/25/patch-release-gitlab-18-9-1-released/ CVE record · GitLab · Updated 2026-02-25T20:05:05.289Z
NVD · CVE-2026-1388 · Updated 2026-06-17T10:15:41.497 - https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-8721 EUVD · EUVD-2026-8721
Technical & other
- https://gitlab.com/gitlab-org/gitlab/-/issues/587560 CVE record · GitLab · Updated 2026-02-25T20:05:05.289Z
NVD · CVE-2026-1388 · Updated 2026-06-17T10:15:41.497
Sources: NVD · CVE.org · All sources and attribution · EPSS