An IDOR exists in < 12.3.2, < 12.2.6, and < 12.1.12 for GitLab Community Edition (CE) and Enterprise Edition (EE) that allowed a project owner or maintainer to see the members of any private group via merge request approval rules.
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2019-15581.json"