mdast-util-to-hast unsanitized class attribute_CVE-2025-66400

6.9 / 10

MEDIUM

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

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.

Basic Information

ID CVE-2025-66400

Source GitHub_M

Published Dec 1, 2025 at 22:17

Affected Product

Vendor syntax-tree

Product mdast-util-to-hast

Version >= 13.0.0, < 13.2.1

Affected Versions syntax-tree mdast-util-to-hast >= 13.0.0, < 13.2.1

CWE Classification

CWE-20 CWE-915

References

{
    "lastseen": "",
    "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.",
    "published": "2025-12-01T22:17:42.705Z",
    "modified": "2025-12-01T22:17:42.705Z",
    "type": "cve",
    "title": "mdast-util-to-hast unsanitized class attribute",
    "source": "GitHub_M",
    "references": "https://github.com/syntax-tree/mdast-util-to-hast/security/advisories/GHSA-4fh9-h7wg-q85m\nhttps://github.com/syntax-tree/mdast-util-to-hast/commit/6fc783ae6abdeb798fd5a68e7f3f21411dde7403\nhttps://github.com/syntax-tree/mdast-util-to-hast/commit/ab3a79570a1afbfa7efef5d4a0cd9b5caafbc5d7",
    "id": "CVE-2025-66400",
    "bulletinFamily": "",
    "cwe": [
        "CWE-20",
        "CWE-915"
    ],
    "cvelist": null,
    "sourceData": "syntax-tree mdast-util-to-hast >= 13.0.0, < 13.2.1",
    "sourceHref": "",
    "cvss": {
        "score": 6.9,
        "severity": "MEDIUM",
        "vector": "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",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "mdast-util-to-hast",
    "version": ">= 13.0.0, < 13.2.1",
    "vendor": "syntax-tree",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}