An issue was discovered in GitLab Community and Enterprise Edition before 11.1.7, 11.2.x before 11.2.4, and 11.3.x before 11.3.1. There is stored XSS on the merge request page via project import.
https://about.gitlab.com/releases/2018/10/01/security-release-gitlab-11-dot-3-dot-1-released/