What is CVE-2026-66010?

CVE-2026-66010 is a medium-severity vulnerability in Cure53 Dompurify, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-07-24.

How severe is CVE-2026-66010?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Cure53 Dompurify

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.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (11.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Cure53 Dompurify — versions 0, 3.4.12

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

disclosure@vulncheck.com (Exploit, vendor-advisory, Vendor Advisory)
disclosure@vulncheck.com (Third Party Advisory, third-party-advisory)

Frequently asked questions

What is CVE-2026-66010?: CVE-2026-66010 is a medium-severity vulnerability in Cure53 Dompurify, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-07-24.
How severe is CVE-2026-66010?: Medium severity. CVSS v3 base score is 6.1 out of 10.