GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.6 before 19.1.8, 19.2 before 19.2.6, and 19.3 before 19.3.2 that under certain conditions could have allowed an authenticated user to bypass SAML SSO sign-in restrictions and authenticate without SSO due to missing authentication enforcement checks.
Credits
Thanks [theluci](https://hackerone.com/theluci) for reporting this vulnerability through our HackerOne bug bounty program