Medium 5.3Published May 26, 2026

CVE-2026-44896Mistune: XSS via unescaped figclass/figwidth in Figure directive

Updated under an hour ago (Oct 26, 2026, 5:00 PM ET)

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It affects lepture mistune and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for lepture mistune

Exploited in the last 30 days

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.

CVSS: 5.3 MEDIUM (v4.0, CNA)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
Weakness (CWE): CWE-79
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Modified
Record last updated: Jun 8, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

lepture mistune lepture:mistune (from the name)	before 3.2.1	CNA record
mistune_project mistune mistune_project:mistune	through 3.2.0	NVD

References

References

https://github.com/lepture/mistune/security/advisories/GHSA-58cw-g322-p94v	x-refsource-confirm, vendor-advisory
https://github.com/lepture/mistune/commit/a3cb6e5655308797e8be021d6c7b5bab13cbace2	x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.