GitLab Community and Enterprise Edition 11.x before 11.3.13, 11.4.x before 11.4.11, and 11.5.x before 11.5.4 has Incorrect Access Control.
https://gitlab.com/gitlab-org/gitlab-ce/issues/55200
https://about.gitlab.com/blog/categories/releases/
https://about.gitlab.com/2018/12/13/critical-security-release-gitlab-11-dot-5-dot-4-released/