CVE-2020-5238: Fedoraproject Fedora

Medium severity, CVSS 6.5. EPSS: 1.6% chance of exploitation in the next 30 days.

The table extension in GitHub Flavored Markdown before version 0.29.0.gfm.1 takes O(n * n) time to parse certain inputs. An attacker could craft a markdown table which would take an unreasonably long time to process, causing a denial of service. This issue does not affect the upstream cmark project. The issue has been fixed in version 0.29.0.gfm.1.

Affected products

• Fedoraproject Fedora: version 31 only; version 32 only; version 33 only
• GitHub Flavored Markdown Project GitHub Flavored Markdown: before 0.29.0.gfm.1 (fixed in 0.29.0.gfm.1)

Published 2020-07-01. Last modified 2026-06-17.