VDB
Sign up
MEDIUM5.3

GHSA-4fh9-h7wg-q85m

mdast-util-to-hast has unsanitized class attribute

Quick fix

GHSA-4fh9-h7wg-q85m — mdast-util-to-hast: upgrade to the fixed version with the command below.

npm install mdast-util-to-hast@13.2.1

Details

### 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:

````markdown ```js xss ``` ````

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

* bug introduced in https://github.com/syntax-tree/mdast-util-to-hast/commit/6fc783ae6abdeb798fd5a68e7f3f21411dde7403 * bug fixed in https://github.com/syntax-tree/mdast-util-to-hast/commit/ab3a79570a1afbfa7efef5d4a0cd9b5caafbc5d7

Are you affected?

Enter the version of the package you're using.

Affected packages

npm/mdast-util-to-hast
Introduced in: 13.0.0Fixed in: 13.2.1
Fixnpm install mdast-util-to-hast@13.2.1

References