CVE-2026-44896: Mistune Project Mistune

Medium severity, CVSS 6.1. EPSS: 0.3% chance of exploitation in the next 30 days.

Mistune is a Python Markdown parser with renderers and plugins. In 3.2.0 and earlier, in src/mistune/directives/image.py, the render_figure() function concatenates figclass and figwidth options directly into HTML attributes without escaping. This allows attribute injection and XSS even when HTMLRenderer(escape=True) is used, because these values bypass the inline renderer. Version 3.2.1 contains a patch.

Affected products

• Mistune Project Mistune: up to and including 3.2.0

Published 2026-05-26. Last modified 2026-07-24.