An issue was discovered in GitLab Community and Enterprise Edition 10.2 through 11.11. Multiple features contained Server-Side Request Forgery (SSRF) vulnerabilities caused by an insufficient validation to prevent DNS rebinding attacks.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2019-4052
https://about.gitlab.com/releases/2019/06/03/security-release-gitlab-11-dot-11-dot-1-released/