VULNERABILITY INTELLIGENCE

CVE-2026-66010

CVSS score6.1 MEDIUM
EPSS probability0.21%
CISA KEVNot currently listed
Published2026-07-24
Last modified2026-10-24
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Description

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.

Weakness classification

  • disclosure@vulncheck.com: CWE-79

Primary references