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Vulnerability Intelligence

CVE-2025-66400

MEDIUM6.9

mdast-util-to-hast unsanitized class attribute

Published Dec 1, 2025

Modified 1 months ago

No fix available

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

WEBhttps://github.com/syntax-tree/mdast-util-to-hast/commit/6fc783ae6abdeb798fd5a68e7f3f21411dde7403 WEBhttps://github.com/syntax-tree/mdast-util-to-hast/commit/ab3a79570a1afbfa7efef5d4a0cd9b5caafbc5d7 WEBhttps://github.com/syntax-tree/mdast-util-to-hast/security/advisories/GHSA-4fh9-h7wg-q85m ADVISORYhttps://www.cve.org/CVERecord?id=CVE-2025-66400

CVSS Analysis

CVSS v4.0

6.9

Exploitability

Attack Vector

NetworkAV:N

Attack Complexity

LowAC:L

Attack Requirements

NoneAT:N

Privileges Required

NonePR:N

User Interaction

NoneUI:N

Vulnerable System

Vuln. Confidentiality

NoneVC:N

Vuln. Integrity

LowVI:L

Vuln. Availability

NoneVA:N

Subsequent System

Subseq. Confidentiality

NoneSC:N

Subseq. Integrity

NoneSI:N

Subseq. Availability

NoneSA:N

6.9/CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

Weakness Type (CWE)

Input Validation

Improper Input Validation

Mass Assignment

Ecosystems

Timeline

PublishedDec 1, 2025

ModifiedDec 2, 2025

CVE-2025-66400 | Mondoo Vulnerability Intelligence