CVE-2026-41238 Details
Description
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.
A vulnerability exists in DOMPurify, a sanitizer for HTML, MathML, and SVG, specifically in versions 3.0.1 through 3.3.3. This issue allows for a cross-site scripting (XSS) bypass through prototype pollution. When 'DOMPurify.sanitize()' is called with the default settings, a previously exploited prototype pollution can introduce lenient regex values for 'tagNameCheck' and 'attributeNameCheck' into 'Object.prototype'. This manipulation enables DOMPurify to sanitize arbitrary custom elements and attributes, including event handlers. The vulnerability arises because the default configuration does not properly handle custom element processing, allowing polluted prototype values to bypass sanitization controls.
Users can upgrade to DOMPurify version 3.4.0, which addresses the vulnerability by preventing prototype pollution through the 'CUSTOM_ELEMENT_HANDLING' option. Alternatively, applications can explicitly set 'CUSTOM_ELEMENT_HANDLING' to null or provide specific checks to mitigate the risk.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Apr 23, 2026CISA-ADP
Assessed Apr 23, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/cure53/DOMPurify/security/advisories/GHSA-v9jr-rg53-9pgp | CISA-ADP | AdvisoryExploitRemedyVendor |
| https://github.com/cure53/DOMPurify/releases/tag/3.4.0 | [email protected] | Release NotesVendor |
| https://github.com/cure53/DOMPurify/security/advisories/GHSA-v9jr-rg53-9pgp | [email protected] | AdvisoryExploitRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-1321 | Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') | [email protected] |
| CWE-79 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| cure53 DOMPurify | >= 3.0.1, <= 3.3.3 (semver) |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Apr 23, 2026 | CVE Modified | CISA-ADP |
| Apr 23, 2026 | New CVE Received | [email protected] |