VulnerabilityDeferred

CVE-2026-41238

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG.

MEDIUM 6.9EPSS 0.22%

Does this matter?

Lower severity and a low EPSS score (0.22%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1: 6.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N
EPSS: 0.22% probability · 13th percentile
CISA KEV: Not listed
Weakness: CWE-79, CWE-1321
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.