Improper authentication exists in < 12.3.2, < 12.2.6, and < 12.1.12 for GitLab Community Edition (CE) and Enterprise Edition (EE) in the GitLab SAML integration had a validation issue that permitted an attacker to takeover another user's account.
A authentication bypass vulnerability exists in GitLab CE/EE
An issue was discovered in GitLab Community and Enterprise Edition through 12.2.1. Certain account actions needed improved authentication and session management.
An authentication issue was discovered in GitLab that allowed a bypass of email verification. This was addressed in GitLab 12.1.2 and 12.0.4.