What’s Vulnerable › Vulnerabilities

CVE-2026-116803: DOMPurify before 3.4.17 DOM XSS via IN_PLACE Hook-Detached Subtrees

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-26 · updated 2026-10-31
• Weakness: CWE-79

Description

DOMPurify before 3.4.17 contains a cross-site scripting vulnerability that allows attackers to keep event handlers armed when an IN_PLACE hook removes a parent or sibling node. Attacker markup in detached subtrees is never walked or neutralized, so handlers like img onerror fire after sanitize() returns, causing DOM XSS.

Affected products

• Npm Dompurify: before 3.4.17 — fixed in 3.4.17
• cure53 DOMPurify: before 3.4.17 — fixed in 3.4.17

How to fix

Upgrade to a fixed version: Npm Dompurify 3.4.17; cure53 DOMPurify 3.4.17. Check the vendor advisory for mitigations.

References

• https://github.com/cure53/DOMPurify/security/advisories/GHSA-mrv2-3pqr-j5jr
• https://www.vulncheck.com/advisories/dompurify-before-3.4.17-dom-xss-via-in-place-hook-detached-subtrees
• https://github.com/cure53/DOMPurify/security/advisories/GHSA-mrv2-3pqr-j5jr

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