# CVE-2026-41238

> Vulnerability · severity: **MEDIUM** (CVSS 6.9).

## 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.

## Key facts

- **CVE ID:** CVE-2026-41238
- **Published:** 2026-04-23
- **CVSS severity:** MEDIUM
- **CVSS base score:** 6.9
- **CWE codes:** CWE-79, CWE-1321

## Primary sources

- NIST NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-41238

## Citation

> AI Analytics. CVE-2026-41238. Retrieved 2026-07-18 from https://api.ai-analytics.org/cve/CVE-2026-41238. Derived from NIST NVD. Licensed CC0.

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