Mistune: Potential DoS via quadratic-time parsing in parse_link_text

Date Jul 9, 2026
Type Vendor advisory
Signal High-risk advisory
Vendor / Product PyPI ยท mistune
CVE CVE-2026-49851
High-risk advisory CVE-2026-49851

Summary

Mistune: Potential DoS via quadratic-time parsing in parse_link_text

Why it matters

GitHub has published a reviewed security advisory for mistune. Prioritize it with other application dependency updates, especially because EPSS places it in the 27% percentile.

Operator check

Check whether mistune is present in application dependency manifests, lockfiles, or build images. Review the GitHub advisory and upgrade to a patched version where available. CVSS score: 8.7. EPSS probability: 0.4%; percentile: 27%.

Sources

PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.