CVE-2026-41238

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Versions 3.0.1 through 3.3.3 are vulnerable to a prototype pollution-based XSS bypass. When an application uses `DOMPurify.sanitize()` with the default configuration (no `CUSTOM_ELEMENT_HANDLING` option), a prior prototype pollution gadget can inject permissive `tagNameCheck` and `attributeNameCheck` regex values into `Object.prototype`, causing DOMPurify to allow arbitrary custom elements with arbitrary attributes — including event handlers — through sanitization. Version 3.4.0 fixes the issue.

CVSS v3 6.9 MEDIUM

6.9^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.6 / Impact : 4.7

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/cure53/DOMPurify/releases/tag/3.4.0
https://github.com/cure53/DOMPurify/security/advisories/GHSA-v9jr-rg53-9pgp
https://github.com/cure53/DOMPurify/security/advisories/GHSA-v9jr-rg53-9pgp

Configurations

No configuration.

History

26 Oct 2026, 22:10

Type	Values Removed	Values Added
Summary		(es) DOMPurify es un saneador de cross-site scripting solo para DOM para HTML, MathML y SVG. Las versiones 3.0.1 a 3.3.3 son vulnerables a un bypass de XSS basado en contaminación de prototipos. Cuando una aplicación utiliza DOMPurify.sanitize() con la configuración predeterminada (sin la opción CUSTOM_ELEMENT_HANDLING), un gadget de contaminación de prototipos previo puede inyectar valores regex permisivos de tagNameCheck y attributeNameCheck en Object.prototype, haciendo que DOMPurify permita elementos personalizados arbitrarios con atributos arbitrarios -incluidos los manejadores de eventos- a través de la sanitización. La versión 3.4.0 corrige el problema.

Information

Published : 2026-04-23 16:16

Updated : 2026-10-26 22:10

NVD link : CVE-2026-41238

Mitre link : CVE-2026-41238

CVE.ORG link : CVE-2026-41238

JSON object : View

Products Affected

No product.

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CWE-1321

Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

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