CVE-2025-66400

MEDIUM6.9

mdast-util-to-hast unsanitized class attribute

Published Dec 1, 2025

Modified 3 months ago

Details

mdast-util-to-hast is an mdast utility to transform to hast. From 13.0.0 to before 13.2.1, multiple (unprefixed) classnames could be added in markdown source by using character references. This could make rendered user supplied markdown code elements appear like the rest of the page. This vulnerability is fixed in 13.2.1.

References

WEB

https://github.com/syntax-tree/mdast-util-to-hast/commit/6fc783ae6abdeb798fd5a68e7f3f21411dde7403

WEB

https://github.com/syntax-tree/mdast-util-to-hast/commit/ab3a79570a1afbfa7efef5d4a0cd9b5caafbc5d7

WEB

https://github.com/syntax-tree/mdast-util-to-hast/security/advisories/GHSA-4fh9-h7wg-q85m

ADVISORY

https://www.cve.org/CVERecord?id=CVE-2025-66400

CVSS Analysis

CVSS v4.0

6.9