VULNERABILITY INTELLIGENCE
CVE-2026-59929
CVSS score6.1 MEDIUM
EPSS probability0.34%
CISA KEVNot currently listed
Published2026-07-08
Last modified2026-10-25
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Description
Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the safe_url filter in src/mistune/renderers/html.py blocks only javascript:, vbscript:, file:, and data: schemes, allowing legacy or chained schemes such as feed:, view-source:, jar:, livescript:, mocha:, ms-its:, mk:, and res: to reach rendered href and src attributes and potentially execute script in affected user agents. This issue is fixed in version 3.3.0.
Weakness classification
- security-advisories@github.com: CWE-79
Primary references
- security-advisories@github.com — Patch
- security-advisories@github.com — Release Notes
- security-advisories@github.com — Exploit, Third Party Advisory