An issue has been discovered in GitLab CE/EE affecting all versions starting from 10.0 before 16.0.8, all versions starting from 16.1 before 16.1.3, all versions starting from 16.2 before 16.2.2. A reflected XSS was possible when creating specific PlantUML diagrams that allowed the attacker to perform arbitrary actions on behalf of victims.
Credits
Thanks [ankitsingh](https://hackerone.com/ankitsingh) for reporting this vulnerability through our HackerOne bug bounty program