An issue was discovered in GitLab Community Edition 11.9.x before 11.9.10 and 11.10.x before 11.10.2. It allows Information Disclosure. When an issue is moved to a private project, the private project namespace is leaked to unauthorized users with access to the original issue.
https://gitlab.com/gitlab-org/gitlab-ce/issues/58939
https://about.gitlab.com/2019/04/29/security-release-gitlab-11-dot-10-dot-2-released/