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CVE-2026-66010

DOMPurify before 3.4.12 Hook Bypass via CUSTOM_ELEMENT_HANDLING

Published: Jul 24, 2026Updated: Aug 6, 2026 Sources: CVE List NVDCWE-79
6.1MEDIUM
NVD MITRE
EPSS Score
0.2%
Top 93.9%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
Not available

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:RS:CC:LI:LA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:RUser Interaction
Required
Scope
S:CScope
Changed
Impact
C:LConfidentiality
Low
I:LIntegrity
Low
A:NAvailability
None
Open in CVSS calculator →

Weaknesses

CWE-79

Affected Products

cure53
aka dompurify
DOMPurifyLibrary
OSS Libraries / generic-library
and 1 more affected products View all →

Exploitability

Official Patch Available

Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques
Execution
Initial Access
View detailed technique mapping

References

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

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