CVE-2026-65904

DOMPurify through 3.3.3 fails to sanitize DOM elements passed via IN_PLACE mode when the element originates from a different window/realm (e.g., an iframe's contentDocument). A cross-realm instanceof check in the private _isNode() function returns false for foreign-realm nodes, causing DOMPurify to stringify the element (yielding '[object HTMLDivElement]'), silently reset IN_PLACE to false, and return the unsanitized element unchanged with any XSS payloads intact.

CVSS v3 4.7 MEDIUM

4.7^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.6 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/cure53/DOMPurify/security/advisories/GHSA-4w3q-35jp-p934	Exploit Third Party Advisory
https://www.vulncheck.com/advisories/dompurify-before-cross-site-scripting-via-in-place-mode	Third Party Advisory
https://github.com/cure53/DOMPurify/security/advisories/GHSA-4w3q-35jp-p934	Exploit Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:cure53:dompurify:*:*:*:*:*:*:*:*

History

24 Oct 2026, 13:10

Type	Values Removed	Values Added
Summary		(es) DOMPurify hasta la versión 3.3.3 no logra sanear elementos DOM pasados a través del modo IN_PLACE cuando el elemento se origina de una ventana/ámbito diferente (p. ej., el contentDocument de un iframe). Una verificación instanceof entre ámbitos en la función privada _isNode() devuelve falso para nodos de ámbito externo, lo que provoca que DOMPurify convierta el elemento en cadena (resultando en ’[object HTMLDivElement]’), restablezca silenciosamente IN_PLACE a falso y devuelva el elemento no saneado sin cambios con cualquier carga útil XSS intacta.

Information

Published : 2026-07-23 14:18

Updated : 2026-10-24 13:10

NVD link : CVE-2026-65904

Mitre link : CVE-2026-65904

CVE.ORG link : CVE-2026-65904

JSON object : View

Products Affected

cure53

dompurify

CWE

CWE-754

Improper Check for Unusual or Exceptional Conditions

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