VULNERABILITY INTELLIGENCE

CVE-2026-59930

CVSS score4.3 MEDIUM
EPSS probability0.19%
CISA KEVNot currently listed
Published2026-07-08
Last modified2026-10-25
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Description

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the toc plugin and TableOfContents directive generate heading IDs as predictable toc_N values without slugifying the heading text, allowing attacker-controlled id="toc_N" content to collide with generated anchors and redirect same-page navigation, CSS selectors, or JavaScript handlers. This issue is fixed in version 3.3.0.

Weakness classification

  • security-advisories@github.com: CWE-345

Primary references