An issue has been discovered in GitLab affecting all versions starting from 13.0 before 14.0.9, all versions starting from 14.1 before 14.1.4, all versions starting from 14.2 before 14.2.2. A user account with 'external' status which is granted 'Maintainer' role on any project on the GitLab instance where 'project tokens' are allowed may elevate its privilege to 'Internal' and access Internal projects.
https://hackerone.com/reports/1193062
https://gitlab.com/gitlab-org/gitlab/-/issues/331473
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-22263.json