CVE-2026-49978 DOMPurify IN_PLACE Sanitization Bypass via Attached Shadow Root Inside <template>.content

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.7, DOMPurify INPLACE sanitization could skip shadow contents attached to an element inside .content, allowing attacker-controlled markup such as event handlers, JavaScript URLs, or scripts to survive an...