CVE-2026-66010 DOMPurify before 3.4.12 Hook Bypass via CUSTOM_ELEMENT_HANDLING

DOMPurify before 3.4.12 fails to execute afterSanitizeElements hook for custom elements allowed via CUSTOMELEMENTHANDLING.tagNameCheck, allowing attributes to bypass application security policies. Attackers can preserve sensitive attributes on custom elements that later re-inject them into...

CVE-2026-65898 DOMPurify before 3.4.11 Permanent Attribute Allowlist Pollution via setConfig

DOMPurify before 3.4.11 fails to clone the ALLOWEDATTR allowlist when setConfig is used with an uponSanitizeAttribute hook, allowing the hook to permanently mutate the shared allowlist. Attackers can register a hook that conditionally allows dangerous attributes like onerror for trusted elements,...