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CVE-2026-41238

CVE-2026-41238 · DOMPurify: Prototype Pollution to XSS Bypass via CUSTOM_ELEMENT_HANDLING Fallback

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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 6.9 · Medium · EPSS 0.3% · Fix available

Published
Updated

Stack: system · node

Affected products and versions

  • dompurify

    Versions
    • >= 3.0.1, < 3.4.0: Affected

    No fix published

  • node-dompurify Debian:12

    Versions
    • 2.4.1+dfsg+~2.4.0-1
    • 2.4.1+dfsg+~2.4.0-2
    • 2.4.1+dfsg+~2.4.0-2+deb12u1
    • 3.0.9+dfsg+~3.0.5-1
    • 3.1.6+dfsg+~3.0.5-1
    • 3.1.7+dfsg+~3.0.5-1
    • 3.1.7+dfsg+~3.0.5-2
    • 3.2.5+dfsg-1
    • 3.3.2+dfsg-1
    • 3.3.3+dfsg-1
    • 3.3.3+dfsg-2
    • 3.4.1+dfsg-1
    • 3.4.12+dfsg-1
    • 3.4.13+dfsg-1
    • 3.4.13+dfsg-2
    • 3.4.16+dfsg-1
    • 3.4.2+dfsg-1
    • 3.4.5+dfsg-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-dompurify Debian:13

    Versions
    • 3.1.7+dfsg+~3.0.5-2
    • 3.2.5+dfsg-1
    • 3.3.2+dfsg-1
    • 3.3.3+dfsg-1
    • 3.3.3+dfsg-2
    • 3.4.1+dfsg-1
    • 3.4.12+dfsg-1
    • 3.4.13+dfsg-1
    • 3.4.13+dfsg-2
    • 3.4.16+dfsg-1
    • 3.4.2+dfsg-1
    • 3.4.5+dfsg-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-dompurify Debian:14

    Versions
    • 3.1.7+dfsg+~3.0.5-2
    • 3.2.5+dfsg-1
    • 3.3.2+dfsg-1
    • 3.3.3+dfsg-1
    • 3.3.3+dfsg-2
    Affected ranges
    • ECOSYSTEM: < 3.4.1+dfsg-1

    Update to 3.4.1+dfsg-1

  • dompurify npm

    Affected ranges
    • SEMVER: ≥ 3.0.1, < 3.4.0

    Update to 3.4.0

  • node-dompurify Ubuntu:22.04:LTS

    Versions
    • 2.3.0+dfsg-2
    • 2.3.3+dfsg-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-dompurify Ubuntu:24.04:LTS

    Versions
    • 2.4.1+dfsg+~2.4.0-1
    • 3.0.9+dfsg+~3.0.5-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-dompurify Ubuntu:25.10

    Versions
    • 3.1.7+dfsg+~3.0.5-1
    • 3.1.7+dfsg+~3.0.5-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-dompurify Ubuntu:26.10

    Versions
    • 3.3.3+dfsg-1
    • 3.4.2+dfsg-1
    • 3.4.5+dfsg-1
    • 3.4.12+dfsg-1
    • 3.4.13+dfsg-1
    • 3.4.13+dfsg-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-dompurify Ubuntu:26.04:LTS

    Versions
    • 3.1.7+dfsg+~3.0.5-2
    • 3.3.3+dfsg-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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