CVE-2026-16255

Incorrect Authorization in GitLab

Published Oct 21, 2026 CVSS 3.1 · 5.9 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

Vendor Solution

Upgrade to versions 19.3.6, 19.4.3, 19.5.1 or above.

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
CPEs cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:*
cpe:2.3:a:gitlab:gitlab:19.5.0:*:*:*:enterprise:*:*:*
Type Values Removed Values Added
Description 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.
Title Incorrect Authorization in GitLab
First Time appeared Gitlab
Gitlab gitlab
Weaknesses CWE-863
CPEs cpe:2.3:a:gitlab:gitlab:*:*:*:*:*:*:*:*
Vendors & Products Gitlab
Gitlab gitlab
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitLab
Published
Updated
Oct 30, 2026, 5:18 PM
Reserved
Jul 20, 2026, 8:04 AM
Status
Analyzed
Published
Oct 22, 2026, 1:16 AM
Modified
Nov 4, 2026, 11:10 PM