CVE-2026-66010 — MEDIUM (6.1)

Q: How severe is CVE-2026-66010?

CVE-2026-66010 has been rated MEDIUM with a CVSS base score of 6.1/10. Review the CVSS metrics above for detailed severity breakdown.

Q: Is there a patch for CVE-2026-66010?

Check the references section above for vendor advisories and patch information. Affected products include: Cure53 Dompurify.

Vulnerability 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.

CVSS Score

6.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

CHANGED

Confidentiality

LOW

Integrity

LOW

Availability

NONE

Affected Products

Vendor	Product	Versions
Cure53	Dompurify	< 3.4.12

Related Weaknesses (CWE)

CWE-79

References

https://github.com/cure53/DOMPurify/security/advisories/GHSA-c2j3-45gr-mqc4ExploitVendor Advisory
https://www.vulncheck.com/advisories/dompurify-before-hook-bypass-via-custom-eleThird Party Advisory
https://github.com/cure53/DOMPurify/security/advisories/GHSA-c2j3-45gr-mqc4ExploitVendor Advisory

FAQ

What is CVE-2026-66010?

CVE-2026-66010 is a vulnerability with a CVSS score of 6.1 (MEDIUM). 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. A...

How severe is CVE-2026-66010?

CVE-2026-66010 has been rated MEDIUM with a CVSS base score of 6.1/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-66010?

Check the references section above for vendor advisories and patch information. Affected products include: Cure53 Dompurify.