Cross-site Scripting (XSS) Affecting mistune package, versions *


Severity

Recommended
low

Based on Debian security rating.

Threat Intelligence

EPSS
0.34% (27th percentile)

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  • Snyk IDSNYK-DEBIAN11-MISTUNE-17896805
  • published9 Jul 2026
  • disclosed8 Jul 2026

Introduced: 8 Jul 2026

CVE-2026-59929  (opens in a new tab)
CWE-79  (opens in a new tab)
CWE-184  (opens in a new tab)

How to fix?

There is no fixed version for Debian:11 mistune.

NVD Description

Note: Versions mentioned in the description apply only to the upstream mistune package and not the mistune package as distributed by Debian. See How to fix? for Debian:11 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1