Cross-Site Scripting

Overview

Versions of dompurify prior to 2.0.3 are vulnerable to Cross-Site Scripting (XSS). The package has an XSS filter bypass due to Mutation XSS in both Chrome and Safari through a combination of <svg>/<math> elements and </p>/</br>. An example payload is: &lt;svg&gt;</p>&lt;style&gt;<a>. This allows attackers to bypass the XSS protection and execute arbitrary JavaScript in a victim’s browser.

Recommendation

Upgrade to version 2.0.3 or later. You may also disallow <svg> and <math> through dompurify configurations:

     FORBID_TAGS: ['svg', 'math']
 });```

## References

- [Vulnerability Report by Securitum](https://research.securitum.com/dompurify-bypass-using-mxss/)
- [GitHub Advisory](https://github.com/advisories/GHSA-chqj-j4fh-rw7m)