An issue has been discovered in GitLab EE affecting all versions starting from 15.1 before 15.7.8, all versions starting from 15.8 before 15.8.4, all versions starting from 15.9 before 15.9.2. If a group with SAML SSO enabled is transferred to a new namespace as a child group, it's possible previously removed malicious maintainer or owner of the child group can still gain access to the group via SSO or a SCIM token to perform actions on the group.
Credits
Thanks [vaib25vicky](https://hackerone.com/vaib25vicky) for reporting this vulnerability through our HackerOne bug bounty program
