An issue has been discovered in GitLab CE/EE affecting all versions starting from 13.9. A specially crafted import file could read files on the server.
https://hackerone.com/reports/1132378
https://gitlab.com/gitlab-org/gitlab/-/issues/325562
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-22201.json