An issue has been discovered in GitLab CE/EE affecting all versions starting from 10.1 before 15.10.8, all versions starting from 15.11 before 15.11.7, all versions starting from 16.0 before 16.0.2. A user could use an unverified email as a public email and commit email by sending a specifically crafted request on user update settings.
https://hackerone.com/reports/1881598
https://gitlab.com/gitlab-org/gitlab/-/issues/394745
https://gitlab.com/gitlab-org/cves/-/blob/master/2023/CVE-2023-1204.json