An issue has been discovered in GitLab CE/EE affecting all versions starting from 15.4 before 15.10.8, all versions starting from 15.11 before 15.11.7, all versions starting from 16.0 before 16.0.2. A DollarMathPostFilter Regular Expression Denial of Service in was possible by sending crafted payloads to the preview_markdown endpoint.
https://hackerone.com/reports/1934711
https://gitlab.com/gitlab-org/gitlab/-/issues/407586
https://gitlab.com/gitlab-org/cves/-/blob/master/2023/CVE-2023-2132.json