Описание
mdast-util-to-hast has unsanitized class attribute
Impact
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.
The following markdown:
Would create <pre><code class="language-js xss"></code></pre>
If your page then applied .xss classes (or listeners in JS), those apply to this element.
For more info see https://github.com/ChALkeR/notes/blob/master/Improper-markup-sanitization.md#unsanitized-class-attribute
Patches
The bug was patched. When using regular semver, run npm install. For exact ranges, make sure to use 13.2.1.
Workarounds
Update.
References
Ссылки
- https://github.com/syntax-tree/mdast-util-to-hast/security/advisories/GHSA-4fh9-h7wg-q85m
- 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/commit/ab3a79570a1afbfa7efef5d4a0cd9b5caafbc5d7
Пакеты
mdast-util-to-hast
>= 13.0.0, < 13.2.1
13.2.1
EPSS
6.9 Medium
CVSS4
5.3 Medium
CVSS3
CVE ID
Дефекты
Связанные уязвимости
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.
EPSS
6.9 Medium
CVSS4
5.3 Medium
CVSS3