Vulnerability · Published Oct 26, 2026 · Assigned by VulnCheck

CVE-2026-116804DOMPurify from 3.4.4 before 3.4.17 SAFE_FOR_TEMPLATES Bypass via Shadow Root Content

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 7% 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 92.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

DOMPurify from 3.4.4 before 3.4.17 contains a SAFE_FOR_TEMPLATES bypass that lets attackers preserve template expressions in attached shadow roots when using RETURN_DOM, RETURN_DOM_FRAGMENT, or IN_PLACE modes. Attackers can split expressions across text nodes separated by disallowed elements, which merge after removal and are evaluated by downstream template engines for cross-site scripting.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:14	node-dompurify	3.4.17+dfsg-1	DEBIAN-CVE-2026-116804
Ubuntu:22.04:LTS	node-dompurify	no fix listed	UBUNTU-CVE-2026-116804
Ubuntu:24.04:LTS	node-dompurify	no fix listed	UBUNTU-CVE-2026-116804
Ubuntu:26.04:LTS	node-dompurify	no fix listed	UBUNTU-CVE-2026-116804
Ubuntu:26.10	node-dompurify	no fix listed	UBUNTU-CVE-2026-116804
npm	dompurify	3.4.17	GHSA-cg2g-xh64-v4q7

Affected products (as reported)

Vendor	Product	Versions
cure53	DOMPurify	3.4.4 – 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-cg2g-xh64-v4q7) vendor-advisory
VulnCheck Advisory: DOMPurify from 3.4.4 before 3.4.17 SAFE_FOR_TEMPLATES Bypass via Shadow Root Content third-party-advisory