An issue was discovered in GitLab Enterprise Edition (EE) 8.9.0 through 12.6.1. Using the project import feature, it was possible for someone to obtain issues from private projects.
GitLab EE 12.3 through 12.5, 12.4.3, and 12.3.6 allows Denial of Service. Certain characters were making it impossible to create, edit, or view issues and commits.