An issue was discovered in GitLab CE and EE 8.15 through 12.9.2. Members of a group could still have access after the group is deleted.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-11649
Reference (s):
- https://about.gitlab.com/releases/2020/04/14/critical-security-release-gitlab-12-dot-9-dot-3-released/
- https://about.gitlab.com/blog/categories/releases/

