Vulnerability · Published Oct 26, 2026 · Assigned by VulnCheck

CVE-2026-116803DOMPurify before 3.4.17 DOM XSS via IN_PLACE Hook-Detached Subtrees

Medium 6.1

In plain English

A medium-severity cross-site scripting in DOMPurify from cure53. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 6% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.1Medium

Exploit odds (30 days)0.2%top 94.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

DOMPurify before 3.4.17 contains a cross-site scripting vulnerability that allows attackers to keep event handlers armed when an IN_PLACE hook removes a parent or sibling node. Attacker markup in detached subtrees is never walked or neutralized, so handlers like img onerror fire after sanitize() returns, causing DOM XSS.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	node-dompurify	no fix listed	DEBIAN-CVE-2026-116803
Debian:13	node-dompurify	no fix listed	DEBIAN-CVE-2026-116803
Debian:14	node-dompurify	3.4.17+dfsg-1	DEBIAN-CVE-2026-116803
Ubuntu:22.04:LTS	node-dompurify	no fix listed	UBUNTU-CVE-2026-116803
Ubuntu:24.04:LTS	node-dompurify	no fix listed	UBUNTU-CVE-2026-116803
Ubuntu:26.04:LTS	node-dompurify	no fix listed	UBUNTU-CVE-2026-116803
Ubuntu:26.10	node-dompurify	no fix listed	UBUNTU-CVE-2026-116803
npm	dompurify	3.4.17	GHSA-mrv2-3pqr-j5jr

Affected products (as reported)

Vendor	Product	Versions
cure53	DOMPurify	0 – before 3.4.17

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

References

GitHub Security Advisory (GHSA-mrv2-3pqr-j5jr) vendor-advisory
VulnCheck Advisory: DOMPurify before 3.4.17 DOM XSS via IN_PLACE Hook-Detached Subtrees third-party-advisory