In all versions of GitLab CE/EE, there exists a content spoofing vulnerability which may be leveraged by attackers to trick users into visiting a malicious website by spoofing the content in an error response.
https://hackerone.com/reports/504961
https://gitlab.com/gitlab-org/gitlab/-/issues/27241
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39873.json