CVE-2026-66010
Published:July 24, 2026
Updated:July 30, 2026
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 Packages
dompurify (CDN_JS):
Affected version(s) >=0.7.0 <3.4.12Fix Suggestion:
Update to version 3.4.12https://github.com/cure53/DOMPurify.git (GITHUB):
Affected version(s) >=0.1 <3.4.12Fix Suggestion:
Update to version 3.4.12dompurify (NPM):
Affected version(s) >=0.4.0 <3.4.12Fix Suggestion:
Update to version 3.4.12Related Resources (8)
Do you need more information?
Contact UsCVSS v4
Base Score:
5.1
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
ACTIVE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
LOW
Subsequent System Integrity
LOW
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
EPSS
Base Score:
0.17