CVE-2019-12429: 
GitLab vulnerability analysis and mitigation

A security vulnerability was discovered in GitLab CE/EE versions 11.9 and later, identified as CVE-2019-12429. The vulnerability allowed unprivileged users to access metadata of confidential issues, including labels, status, and merge request counts through the milestone details page (GitLab Release).

The vulnerability was related to an access control issue in GitLab's milestone details page functionality. It specifically affected the handling of confidential issue metadata, where the system failed to properly restrict access to sensitive information such as labels, status, and merge request counts (GitLab Release).

The vulnerability allowed unauthorized users to view confidential information about issues they should not have access to, potentially exposing sensitive project information through the milestone details page (GitLab Release).

GitLab addressed this vulnerability in versions 11.11.1, 11.10.5, and 11.9.12. Users running affected versions were strongly recommended to upgrade to these patched versions immediately to prevent unauthorized access to confidential issue metadata (GitLab Release).

The vulnerability was responsibly reported by security researcher @ashish_r_padelkar, leading to a coordinated disclosure and patch release by GitLab (GitLab Release).