What’s Vulnerable › Vulnerabilities

CVE-2026-4398: Authorization Bypass Through User-Controlled Key in GitLab

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-08 · updated 2026-09-28
• Weakness: CWE-639

Description

GitLab 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.

Affected products

• GitLab: from 18.3.0 before 19.1.7; from 19.2.0 before 19.2.5; 19.3.0 — fixed in 19.1.7, 19.2.5

How to fix

Upgrade to a fixed version: GitLab 19.1.7, 19.2.5. Check the vendor advisory for mitigations.

References

• https://docs.gitlab.com/releases/patches/patch-release-gitlab-19-3-1-released/
• https://gitlab.com/gitlab-org/gitlab/-/work_items/600360
• https://hackerone.com/reports/3549150

Get alerted when CVE-2026-4398 or the next vulnerability affects your stack