CVE-2026-66010: CURE53 Dompurify

Medium severity, CVSS 6.1. EPSS: 0.3% chance of exploitation in the next 30 days.

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 innerHTML sinks, creating second-order XSS gadgets.

Affected products

• CURE53 Dompurify: before 3.4.12 (fixed in 3.4.12)

Published 2026-07-24. Last modified 2026-08-06.