CVE-2026-66010

DOMPurify before 3.4.12 has a vulnerability where afterSanitizeElements is not executed for custom elements allowed by CUSTOM_ELEMENT_HANDLING.tagNameCheck, enabling attributes to bypass application security policies. Attackers can preserve sensitive attributes on custom elements and later re-inj...

CVE-2026-66010

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-2026-66010 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-2026-66010

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-2026-66010 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...

PT-2026-64287

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

Incomplete List of Disallowed Inputs

Overview dompurify is a DOM-only XSS sanitizer for HTML, MathML and SVG. Affected versions of this package are vulnerable to Incomplete List of Disallowed Inputs in the CUSTOMELEMENTHANDLING. An attacker can cause security-relevant attributes to be preserved on allowed custom elements by leveragi...

GHSA-C2J3-45GR-MQC4 DOMPurify: `CUSTOM_ELEMENT_HANDLING` bypasses `afterSanitizeElements` for allowed custom elements.

Summary There is a possible hook-policy inconsistency in DOMPurify 3.4.11 involving CUSTOMELEMENTHANDLING. When a custom element is allowed via CUSTOMELEMENTHANDLING.tagNameCheck, it appears that the element does not go through afterSanitizeElements in the same way as a normal element. As a resul...