Vulnerability Description
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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Unifiedjs | Mdast-Util-To-Hast | >= 13.0.0, < 13.2.1 |
Related Weaknesses (CWE)
References
- https://github.com/syntax-tree/mdast-util-to-hast/commit/6fc783ae6abdeb798fd5a68Patch
- https://github.com/syntax-tree/mdast-util-to-hast/commit/ab3a79570a1afbfa7efef5dPatch
- https://github.com/syntax-tree/mdast-util-to-hast/security/advisories/GHSA-4fh9-Vendor Advisory
FAQ
What is CVE-2025-66400?
CVE-2025-66400 is a vulnerability with a CVSS score of 5.3 (MEDIUM). 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 ...
How severe is CVE-2025-66400?
CVE-2025-66400 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-66400?
Check the references section above for vendor advisories and patch information. Affected products include: Unifiedjs Mdast-Util-To-Hast.