PT-2025-48573 · Unknown · Mdast-Util-To-Hast

CVE-2025-66400 · Published 2025-12-01 · Updated 2026-02-06

Positive Technologies (AI Summary)

CVSS v4.0

6.9

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions mdast-util-to-hast versions 13.0.0 through 13.2.0

Description mdast-util-to-hast, a utility used to transform markdown to HTML, has an issue where multiple, unprefixed classnames could be added to markdown source using character references. This could cause user-supplied markdown code elements to visually blend with the rest of the page.

Recommendations Update to version 13.2.1 or later.

Exploit

Fix

RCE

Weakness Enumeration

CWE-20

CWE-915

Related Identifiers

CVE-2025-66400

GHSA-4FH9-H7WG-Q85M

Affected Products

Mdast-Util-To-Hast

References · 14

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66400.json · Exploit
• https://github.com/syntax-tree/mdast-util-to-hast/security/advisories/GHSA-4fh9-h7wg-q85m · Vendor Advisory
• https://github.com/syntax-tree/mdast-util-to-hast/commit/6fc783ae6abdeb798fd5a68e7f3f21411dde7403 · Patch
• https://github.com/syntax-tree/mdast-util-to-hast/commit/ab3a79570a1afbfa7efef5d4a0cd9b5caafbc5d7 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2025-66400 · Security Note
• https://osv.dev/vulnerability/GHSA-4fh9-h7wg-q85m · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2025-66400 · Vendor Advisory
• https://github.com/syntax-tree/mdast-util-to-hast · Note
• https://t.me/CVEtracker/38605 · Telegram Post
• https://twitter.com/CVEnew/status/1995626930855375006 · Twitter Post
• https://t.me/cveNotify/144474 · Telegram Post
• https://t.me/cveNotify/151152 · Telegram Post
• https://t.me/cveNotify/151147 · Telegram Post
• https://reddit.com/r/VulnMatter/comments/1pchx5n/resumen_diario_de_vulnerabilidades_02122025 · Reddit Post