An issue was discovered in GitLab Community and Enterprise Edition 10.x (starting in 10.7) and 11.x before 11.5.8, 11.6.x before 11.6.6, and 11.7.x before 11.7.1. It has Incorrect Access Control. System notes contain an access control issue that permits a guest user to view merge request titles.
https://gitlab.com/gitlab-org/gitlab-ce/issues/53858
https://about.gitlab.com/2019/01/31/security-release-gitlab-11-dot-7-dot-3-released/