CVE-2026-59927 — Mistune directives/include: mutual `.. include::` recursion crashes the renderer with `RecursionError`, denial of service via two attacker-controlled markdown files

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the Include directive in src/mistune/directives/include.py detects only direct self-includes and …

Published: 2026-07-08 · CVSS: 5.3 · CVSS 3.1

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the Include directive in src/mistune/directives/include.py detects only direct self-includes and not indirect cycles, allowing two markdown files that include each other to trigger unbounded recursion, raise RecursionError, and crash the rendering request. This issue is fixed in version 3.3.0.

Original CVE JSON · STIX 2.1

Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7