An issue has been discovered in GitLab CE/EE affecting all versions starting from 11.4 prior to 15.5.7, 15.6 prior to 15.6.4, and 15.7 prior to 15.7.2. GitLab Pages allows redirection to arbitrary protocols.
https://gitlab.com/gitlab-org/gitlab-pages/-/issues/728
https://gitlab.com/gitlab-org/cves/-/blob/master/2023/CVE-2023-0042.json