Information disclosure via GraphQL in GitLab CE/EE 13.1 and later exposes private group and project membership. This affects versions >=13.6 to <13.6.2, >=13.5 to <13.5.5, and >=13.1 to <13.4.7.
https://gitlab.com/gitlab-org/gitlab/-/issues/282539
https://gitlab.com/gitlab-org/cves/-/blob/master/2020/CVE-2020-26417.json