Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, render_admonition() in src/mistune/directives/admonition.py concatenates the Admonition directive :class: option into the HTML class attribute without escaping, allowing attribute injection and cross-site scripting even when HTMLRenderer escape mode is enabled. This issue is fixed in version 3.2.1.
History

Wed, 08 Jul 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 08 Jul 2026 17:45:00 +0000

Type Values Removed Values Added
First Time appeared Lepture
Lepture mistune
Vendors & Products Lepture
Lepture mistune

Wed, 08 Jul 2026 16:30:00 +0000

Type Values Removed Values Added
Description Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, render_admonition() in src/mistune/directives/admonition.py concatenates the Admonition directive :class: option into the HTML class attribute without escaping, allowing attribute injection and cross-site scripting even when HTMLRenderer escape mode is enabled. This issue is fixed in version 3.2.1.
Title Mistune: XSS via unescaped class option in Admonition directive
Weaknesses CWE-79
References
Metrics cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-07-08T19:40:52.229Z

Reserved: 2026-07-07T18:20:06.126Z

Link: CVE-2026-59926

cve-icon Vulnrichment

Updated: 2026-07-08T17:48:33.163Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-07-08T17:30:03Z