In all versions of GitLab CE/EE since version 8.15, a DNS rebinding vulnerability in Gitea Importer may be exploited by an attacker to trigger Server Side Request Forgery (SSRF) attacks.
https://gitlab.com/gitlab-org/gitlab/-/issues/214401
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39867.json