Incorrect Authorization in GitLab EE affecting all versions starting from 11.1 before 14.3.6, all versions starting from 14.4 before 14.4.4, all versions starting from 14.5 before 14.5.2, allows a user to add comments to a vulnerability which cannot be accessed.
https://hackerone.com/reports/1180043
https://gitlab.com/gitlab-org/gitlab/-/issues/329916
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39918.json