An issue was discovered in GitLab Community and Enterprise Edition before 10.8.7, 11.0.x before 11.0.5, and 11.1.x before 11.1.2. XSS can occur in the branch name during a Web IDE file commit.
https://gitlab.com/gitlab-org/gitlab-ce/issues/47793
https://about.gitlab.com/2018/07/26/security-release-gitlab-11-dot-1-dot-2-released/