An issue was discovered in GitLab Community and Enterprise Edition 11.x before 11.2.7, 11.3.x before 11.3.8, and 11.4.x before 11.4.3. It allows Information Exposure via a Gitlab Prometheus integration.
https://about.gitlab.com/2018/10/29/security-release-gitlab-11-dot-4-dot-3-released/