A vulnerability was discovered in GitLab versions before 14.0.2, 13.12.6, 13.11.6. GitLab Webhook feature could be abused to perform denial of service attacks.
https://hackerone.com/reports/1029269
https://gitlab.com/gitlab-org/gitlab/-/issues/280633
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-22246.json