Improper authorization checks in all versions of GitLab EE starting from 13.11 before 14.1.7, all versions starting from 14.2 before 14.2.5, and all versions starting from 14.3 before 14.3.1 allows subgroup members to see epics from all parent subgroups.
https://gitlab.com/gitlab-org/gitlab/-/issues/334279
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39883.json