CVE-2026-16255: GitLab 12.0 to before 19.3.6, 19.4 to before 19.4.3, 19.5 to before 19.5.1

Affected technology

GitLab · 12.0 to before 19.3.6, 19.4 to before 19.4.3, 19.5 to before 19.5.1
GitLab

Component: Not specified by the source

Attack conditions (Vendor/CNA, CVSS 3.1): Network (remote) · Low privileges required · No user interaction required

What an attacker can do

The source says 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. Vendor/CNA’s CVSS 3.1 assessment (base score 5.9/10) rates confidentiality impact as high; integrity impact as low; availability impact as none.