An issue has been discovered in GitLab affecting all versions starting from 12.8 before 15.8.5, all versions starting from 15.9 before 15.9.4, all versions starting from 15.10 before 15.10.1. A specially crafted payload could lead to a reflected XSS on the client side which allows attackers to perform arbitrary actions on behalf of victims on self-hosted instances running without strict CSP.