Vulnerability DatabaseCVE-2025-66400
Mend.io Vulnerability Database
The largest open source vulnerability database
What is a Vulnerability ID?
New vulnerability? Tell us about it!
CVE-2025-66400
December 01, 2025
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.
Affected Packages
mdast-util-to-hast (NPM):
Affected version(s) >=13.0.0 <13.2.1
Fix Suggestion:
Update to version 13.2.1
https://github.com/syntax-tree/mdast-util-to-hast.git (SCM_GIT):
Affected version(s) >=13.0.0 <13.2.1
Fix Suggestion:
Update to version 13.2.1
Related Resources (5)
https://nvd.nist.gov/vuln/detail/CVE-2025-66400
https://github.com/syntax-tree/mdast-util-to-hast/commit/6fc783ae6abdeb798fd5a68e7f3f21411dde7403
https://github.com/syntax-tree/mdast-util-to-hast
https://github.com/syntax-tree/mdast-util-to-hast/commit/ab3a79570a1afbfa7efef5d4a0cd9b5caafbc5d7
https://github.com/syntax-tree/mdast-util-to-hast/security/advisories/GHSA-4fh9-h7wg-q85m
Do you need more information?
Contact Us
CVSS v4
Base Score:
6.9
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Improper Input Validation
CWE-20
Improperly Controlled Modification of Dynamically-Determined Object Attributes
CWE-915
EPSS
Base Score:
0.08