CVE-2026-41240

Name	CVE-2026-41240
Description	DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Versions prior to 3.4.0 have an inconsistency between FORBID_TAGS and FORBID_ATTR handling when function-based ADD_TAGS is used. Commit c361baa added an early exit for FORBID_ATTR at line 1214. The same fix was not applied to FORBID_TAGS. At line 1118-1123, when EXTRA_ELEMENT_HANDLING.tagCheck returns true, the short-circuit evaluation skips the FORBID_TAGS check entirely. This allows forbidden elements to survive sanitization with their attributes intact. Version 3.4.0 patches 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-h7mw-gpvr-xq4m