CVE-2026-66010CWE-79cross-site-scripting

CVE-2026-66010

Medium · published July 24, 2026

CVSS v3.1
6.1
EPSS
0%
Percentile
22.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.1 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00305 · 22.0th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-07-24T17:18Z
Affected products (1)
ProductVersionsFixed in
cure53/dompurify< 3.4.123.4.12
References (3)
https://github.com/cure53/DOMPurify/security/advisories/GHSA-c2j3-45gr-mqc4 · [email protected]https://www.vulncheck.com/advisories/dompurify-before-hook-bypass-via-custom-element-handling · [email protected]https://github.com/cure53/DOMPurify/security/advisories/GHSA-c2j3-45gr-mqc4 · 134c704f-9b21-4f2e-91b3-4a467353bcc0
EPSS history
Timeline
  • 24 JUL 12:07Z
    DOMPurify before 3.4.12 Hook Bypass via CUSTOM_ELEMENT_HANDLING
    cvelistv5