Several quadratic complexity bugs may lead to denial of service in Commonmarker
## Impact
Several quadratic complexity bugs in commonmarker's underlying `cmark-gfm`
https://github.com/github/cmark-gfm library may lead to unbounded resource exhaustion and subsequent denial of service.
The following vulnerabilities were addressed:
* CVE-2023-37463
https://github.com/github/cmark-gfm/security/advisories/GHSA-w4qg-3vf7-m9x5
For more information, consult the release notes for version `0.29.0.gfm.12`
https://github.com/github/cmark-gfm/releases/tag/0.29.0.gfm.12.
## Mitigation
Users are advised to upgrade to commonmarker version `0.23.10`
https://rubygems.org/gems/commonmarker/versions/0.23.10.