PatchTheCVECVE-2026-16255: GitLab has remediated an issue in GitLab EE affecting all versions from 12.0 before 19.3.6, 19.4 before 19.4.3
CVE-2026-16255 is a medium-severity flaw (CVSS 5.9) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
GitLab has remediated an issue in GitLab EE affecting all versions from 12.0 before 19.3.6, 19.4 before 19.4.3, and 19.5 before 19.5.1 that, when the instance-wide SAML or LDAP membership lock was enabled, an authenticated user could have granted or accepted project and group membership outside the identity provider's control, due to incomplete enforcement of the membership lock on requests created before the lock was enabled.
Why this priority
- No elevated risk signals yet
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 5.9 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | High |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 0.2% (top 89%) |
| CISA exploited list | No |
| Weakness | CWE-863 |
| Published | 2026-10-22 |
| Last modified | 2026-10-22 |
Last updated 2026-10-22 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-16255?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-16255 being exploited?
CVE-2026-16255 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-16255 affect?
CVE-2026-16255 affects affected software. Severity is medium (CVSS 5.9). GitLab has remediated an issue in GitLab EE affecting all versions from 12.0 before 19.3.6, 19.4 before 19.4.3, and 19.5 before 19.5.1 that, when the instance-wide SAML or LDAP membership lock was enabled, an authenticated user could have g
How urgent is CVE-2026-16255?
Priority 23/100. No elevated risk signals yet.