CVE-2026-66010

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.

CVSS v3 6.1 MEDIUM

6.1^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/cure53/DOMPurify/security/advisories/GHSA-c2j3-45gr-mqc4
https://www.vulncheck.com/advisories/dompurify-before-hook-bypass-via-custom-element-handling
https://github.com/cure53/DOMPurify/security/advisories/GHSA-c2j3-45gr-mqc4

Configurations

No configuration.

History

24 Jul 2026, 15:19

Type	Values Removed	Values Added
References	~~() https://github.com/cure53/DOMPurify/security/advisories/GHSA-c2j3-45gr-mqc4 -~~	() https://github.com/cure53/DOMPurify/security/advisories/GHSA-c2j3-45gr-mqc4 -

24 Jul 2026, 13:18

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-24 13:18

Updated : 2026-07-30 19:54

NVD link : CVE-2026-66010

Mitre link : CVE-2026-66010

CVE.ORG link : CVE-2026-66010

JSON object : View

Products Affected

No product.

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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