CVE-2026-41238

Name	CVE-2026-41238
Description	DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Versions 3.0.1 through 3.3.3 are vulnerable to a prototype pollution-based XSS bypass. When an application uses `DOMPurify.sanitize()` with the default configuration (no `CUSTOM_ELEMENT_HANDLING` option), a prior prototype pollution gadget can inject permissive `tagNameCheck` and `attributeNameCheck` regex values into `Object.prototype`, causing DOMPurify to allow arbitrary custom elements with arbitrary attributes — including event handlers — through sanitization. Version 3.4.0 fixes the issue.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
node-dompurify (PTS)	bookworm	2.4.1+dfsg+~2.4.0-2+deb12u1	vulnerable
	bookworm (security)	2.4.1+dfsg+~2.4.0-2	vulnerable
	trixie	3.1.7+dfsg+~3.0.5-2	vulnerable
	forky, sid	3.3.3+dfsg-2	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
node-dompurify	source	(unstable)	(unfixed)

https://github.com/cure53/DOMPurify/security/advisories/GHSA-v9jr-rg53-9pgp