Improper access control in GitLab CE/EE version 10.5 and above allowed subgroup members with inherited access to a project from a parent group to still have access even after the subgroup is transferred
https://hackerone.com/reports/1330806
https://gitlab.com/gitlab-org/gitlab/-/issues/341017
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39897.json