CVE-2026-4398
MEDIUM 5.4 ALL-YEARSGitLab has remediated an issue in GitLab EE affecting all versions from 18.3 before 19.1.7, 19.2 before 19.2.5, and 19.3 before 19.3.1 that, under certain conditions, an authenticated user could have assigned compliance frameworks from namespaces they were not authorized to access to their own project, due to missing namespace validation on self-managed instances.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.2%chance of exploitation in 30 days · 15th percentile
Impact if exploited
5.4CVSS 3.1 · MEDIUM · CNA
- ConfidentialityLow
- IntegrityLow
- AvailabilityNone
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires a low-privilege account
- ✓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-639: : Authorization Bypass Through User-Controlled Key
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
References and research data (JSON)
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Gitlab | Gitlab | ≥ 18.3.0 and < 19.1.7 |
| Gitlab | Gitlab | ≥ 19.2.0 and < 19.2.5 |
| Gitlab | Gitlab | 19.3.0 |
All CVSS metrics
- MEDIUM 5.4 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N - MEDIUM 5.4 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
References
Exploit-tagged references (not proof of a PoC)
- https://hackerone.com/reports/3549150 CVE record · GitLab · Updated 2026-08-27T17:53:14.609Z
NVD · CVE-2026-4398 · Updated 2026-09-28T19:09:33.800
Advisories
- https://docs.gitlab.com/releases/patches/patch-release-gitlab-19-3-1-released/ CVE record · GitLab · Updated 2026-08-27T17:53:14.609Z
NVD · CVE-2026-4398 · Updated 2026-09-28T19:09:33.800 - https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-67167 EUVD · EUVD-2026-67167
Technical & other
- https://gitlab.com/gitlab-org/gitlab/-/work_items/600360 CVE record · GitLab · Updated 2026-08-27T17:53:14.609Z
NVD · CVE-2026-4398 · Updated 2026-09-28T19:09:33.800
Sources: NVD · CVE.org · All sources and attribution · EPSS