All versions of GitLab CE/EE starting from 12.8 before 13.10.5, all versions starting from 13.11 before 13.11.5, and all versions starting from 13.12 before 13.12.2 were affected by an issue in the handling of x509 certificates that could be used to spoof author of signed commits.
Credits
Thanks subbotin for reporting this vulnerability through our HackerOne bug bounty program
