CVE-2023-24824: GitHub Cmark-Gfm

High severity, CVSS 7.5. EPSS: 1% chance of exploitation in the next 30 days.

cmark-gfm is GitHub's fork of cmark, a CommonMark parsing and rendering library and program in C. A polynomial time complexity issue in cmark-gfm may lead to unbounded resource exhaustion and subsequent denial of service. This CVE covers quadratic complexity issues when parsing text which leads with either large numbers of `>` or `-` characters. This issue has been addressed in version 0.29.0.gfm.10. Users are advised to upgrade. Users unable to upgrade should validate that their input comes from trusted sources.

Affected products

• GitHub Cmark-Gfm: before 0.29.0.gfm.10. (fixed in 0.29.0.gfm.10.)

Published 2023-03-31. Last modified 2026-06-17.