CVE-2026-49978

MEDIUM6.3

DOMPurify IN_PLACE Sanitization Bypass via Attached Shadow Root Inside <template>.content

Published Jul 14, 2026

Modified 1 weeks ago

Details

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.7, DOMPurify IN_PLACE sanitization could skip shadow contents attached to an element inside <template>.content, allowing attacker-controlled markup such as event handlers, JavaScript URLs, or scripts to survive and execute when an application cloned and inserted the sanitized template. This issue is fixed in version 3.4.7.

References

WEB

https://github.com/cure53/DOMPurify/commit/ca30f070c360df162a3e3848e80e6fd3c9e74bff

WEB

https://github.com/cure53/DOMPurify/releases/tag/3.4.7

WEB

https://github.com/cure53/DOMPurify/security/advisories/GHSA-rp9w-3fw7-7cwq

ADVISORY

https://www.cve.org/CVERecord?id=CVE-2026-49978

CVSS Analysis

CVSS v4.0

6.3