CVE-2026-49458 DOMPurify: Cross-realm IN_PLACE sanitization leaves executable markup intact via realm-bound `instanceof` checks

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.6, DOMPurify.sanitizenode, INPLACE: true accepted same-origin foreign-realm DOM nodes while follow-on checks used parent-realm constructors, causing instanceof checks for forms, named node maps, documen...

CVE-2026-49458

DOMPurify prior to v3.4.6 had a cross-realm IN_PLACE sanitization flaw where instanceof checks across realms allowed executable markup to bypass certain branches; fixed in v3.4.6. Affected: DOMPurify.sanitize with IN_PLACE in multi-realm scenarios. Mitigation: upgrade to DOMPurify 3.4.6 or later....

CVE-2026-49458 DOMPurify: Cross-realm IN_PLACE sanitization leaves executable markup intact via realm-bound `instanceof` checks

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.6, DOMPurify.sanitizenode, INPLACE: true accepted same-origin foreign-realm DOM nodes while follow-on checks used parent-realm constructors, causing instanceof checks for forms, named node maps, documen...

GHSA-HPCV-96WG-7VJ8 DOMPurify: Cross-realm IN_PLACE sanitization leaves executable markup intact via realm-bound `instanceof` checks

Cross-realm INPLACE sanitization leaves executable markup intact via realm-bound instanceof checks CWE: CWE-79 XSS — Improper Neutralization of Input During Web Page Generation via CWE-693 Protection Mechanism Failure — realm-bound instanceof checks fail-open on foreign-realm DOM nodes and CWE-50...

PT-2026-49557

Name of the Vulnerable Software and Affected Versions DOMPurify versions prior to 3.4.6 Description DOMPurify fails to properly sanitize DOM nodes from same-origin foreign realms such as those from an iframe, popup window, or opened tab when using the DOMPurify.sanitizenode, IN PLACE: true method...