---
id: CVE-2026-116803
title: DOMPurify before 3.4.17 DOM XSS via IN_PLACE Hook-Detached Subtrees
summary: >-
  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 neut…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-79
vendor: cure53
product: DOMPurify
affected:
  - DOMPurify < 3.4.17
published: '2026-10-26'
updated: '2026-10-26'
sourceUpdated: '2026-10-26T23:05:35.135Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-116803'
references:
  - url: >-
      https://github.com/cure53/DOMPurify/security/advisories/GHSA-mrv2-3pqr-j5jr
    label: GitHub Security Advisory (GHSA-mrv2-3pqr-j5jr)
  - url: >-
      https://www.vulncheck.com/advisories/dompurify-before-3.4.17-dom-xss-via-in-place-hook-detached-subtrees
    label: >-
      VulnCheck Advisory: DOMPurify before 3.4.17 DOM XSS via IN_PLACE
      Hook-Detached Subtrees
tags:
  - cve.org
epss: 0.00164
epssPercentile: 0.05591
ingestedAt: '2026-10-27T16:11:59.139Z'
---

## Overview

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

- `DOMPurify < 3.4.17`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.