Description
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.
Published: 2026-05-26
Score: 5.3 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-58cw-g322-p94v Mistune has XSS via unescaped figclass/figwidth in Figure directive
History

Mon, 08 Jun 2026 23:45:00 +0000

Type Values Removed Values Added
Description Mistune is a Python Markdown parser with renderers and plugins. In 3.2.0 and realier, 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. 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.
References

Thu, 28 May 2026 13:45:00 +0000

Type Values Removed Values Added
First Time appeared Mistune Project
Mistune Project mistune
CPEs cpe:2.3:a:mistune_project:mistune:*:*:*:*:*:*:*:*
Vendors & Products Mistune Project
Mistune Project mistune
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}


Wed, 27 May 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 26 May 2026 23:30:00 +0000

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

Tue, 26 May 2026 21:15:00 +0000

Type Values Removed Values Added
Description Mistune is a Python Markdown parser with renderers and plugins. In 3.2.0 and realier, 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.
Title Mistune: XSS via unescaped figclass/figwidth in Figure 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:N/VI:N/VA:N/SC:L/SI:L/SA:N'}


Subscriptions

Lepture Mistune
Mistune Project Mistune
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-06-08T23:34:02.448Z

Reserved: 2026-05-07T21:50:33.546Z

Link: CVE-2026-44896

cve-icon Vulnrichment

Updated: 2026-05-27T13:18:49.782Z

cve-icon NVD

Status : Modified

Published: 2026-05-26T21:16:39.477

Modified: 2026-06-17T10:51:29.943

Link: CVE-2026-44896

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-09T01:30:26Z

Weaknesses