Mistune: Denial of Service — RecursionError via Excessive Emphasis Markers in Markdown

Date Sep 2, 2026
Type Vendor advisory
Signal High-risk advisory
Vendor / Product PyPI · mistune
CVE CVE-2026-76098
High-risk advisory CVE-2026-76098

Summary

Mistune: Denial of Service — RecursionError via Excessive Emphasis Markers in Markdown

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 20% 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. EPSS probability: 0.3%; percentile: 20%.

Sources

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