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CVE-2025-66400

MediumCVSS 6.9 / 10
Published Dec 1, 2025·Last modified Apr 2, 2026
Affected Components(0)

No affected components available

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.

Risk Scores
Base Score
6.9

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability.

Threat Intelligence
2.7

Limited exploitation activity has been observed. Close monitoring and planned remediation are recommended.

EPSS
0.27%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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