An issue has been discovered in GitLab CE/EE affecting all versions starting from 15.4 before 15.9.7, all versions starting from 15.10 before 15.10.6, all versions starting from 15.11 before 15.11.2. Under certain conditions, a malicious unauthorized GitLab user may use a GraphQL endpoint to attach a malicious runner to any project.
https://hackerone.com/reports/1969599
https://gitlab.com/gitlab-org/gitlab/-/issues/409470
https://gitlab.com/gitlab-org/cves/-/blob/master/2023/CVE-2023-2478.json