An issue was discovered in GitLab Enterprise Edition 8.3 through 12.0.2. The color codes decoder was vulnerable to a resource depletion attack if specific formats were used. It allows Uncontrolled Resource Consumption.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2019-4583
https://about.gitlab.com/releases/2019/07/03/security-release-gitlab-12-dot-0-dot-3-released/