An issue has been discovered in GitLab CE/EE affecting all versions starting from 13.2 before 14.3.6, all versions starting from 14.4 before 14.4.4, all versions starting from 14.5 before 14.5.2. GitLab Maven Package registry is vulnerable to a regular expression denial of service when a specifically crafted string is sent.
https://hackerone.com/reports/997961
https://gitlab.com/gitlab-org/gitlab/-/issues/263116
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39940.json