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CVE-2026-44897

Mistune Heading ID Attribute Injection XSS PUBLISHED

Description (CNA)

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, HTMLRenderer.heading() builds the opening <hN> tag by string-concatenating the id attribute value directly into the HTML — with no call to escape(), safe_entity(), or any other sanitisation function. A double-quote character " in the id value terminates the attribute, allowing an attacker to inject arbitrary additional attributes (event handlers, src=, href=, etc.) into the heading element. This vulnerability is fixed in 3.2.1.

Affected (CNA)

Vendor / productVersions
lepture / mistuneaffected < 3.2.1

CWE

CWE-79

References

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.