Vulnerability · Published Jul 23, 2026 · Assigned by VulnCheck

CVE-2026-65904DOMPurify through 3.3.3 Cross-Site Scripting via IN_PLACE mode

Medium 4.7

In plain English

A medium-severity security flaw in DOMPurify from cure53. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 19% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)4.7Medium

Exploit odds (30 days)0.3%top 81.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

DOMPurify through 3.3.3 fails to sanitize DOM elements passed via IN_PLACE mode when the element originates from a different window/realm (e.g., an iframe's contentDocument). A cross-realm instanceof check in the private _isNode() function returns false for foreign-realm nodes, causing DOMPurify to stringify the element (yielding '[object HTMLDivElement]'), silently reset IN_PLACE to false, and return the unsanitized element unchanged with any XSS payloads intact.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	node-dompurify	no fix listed	DEBIAN-CVE-2026-65904
Debian:13	node-dompurify	no fix listed	DEBIAN-CVE-2026-65904
Debian:14	node-dompurify	3.4.5+dfsg-1	DEBIAN-CVE-2026-65904
Ubuntu:22.04:LTS	node-dompurify	no fix listed	UBUNTU-CVE-2026-65904
Ubuntu:24.04:LTS	node-dompurify	no fix listed	UBUNTU-CVE-2026-65904
Ubuntu:26.04:LTS	node-dompurify	no fix listed	UBUNTU-CVE-2026-65904

Affected products (as reported)

Vendor	Product	Versions
cure53	DOMPurify	0 – through 3.3.3

Weakness: CWE-754 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N

References

GitHub Security Advisory (GHSA-4w3q-35jp-p934) vendor-advisory
VulnCheck Advisory: DOMPurify before 3.4.4 Cross-Site Scripting via IN_PLACE mode third-party-advisory