CVE-2026-41238
MEDIUM
MEDIUM
Priority: 0.02
BB Relevance:
54/100
Published: 2026-04-23
Modified: 2026-10-26
First seen: 2026-10-29
Status: active
Attack Surface
Network
No Auth
Conf. Impact
Scope Change
CVSS Vector Breakdown
AV:
Network
AC:
High
PR:
None
UI:
Required
S:
Changed
C:
High
I:
Low
A:
None
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.