# DOMPurify DOM XSS in IN_PLACE mode with afterSanitize hooks

Source: https://junglewise.ai/threats/dompurify-in-place-node-removing-aftersanitize-hook-leaves-detached-3087e7fd  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-30. Updated: 2026-09-30  
License: CC BY 4.0 with a link back

Severity: medium · CVSS 4 · Published 2026-09-30

DOMPurify is a JavaScript library that sanitizes HTML to prevent cross-site scripting (XSS) attacks. When used in IN_PLACE mode with afterSanitize hooks, a flaw allows event handlers to persist on detached DOM nodes even after sanitization. An attacker who supplies malicious markup can execute arbitrary JavaScript in the victim's browser session.

Technologies: [Cure53 DOMPurify](https://junglewise.ai/threats/technologies/cure53-dompurify), [dompurify (npm)](https://junglewise.ai/threats/technologies/dompurify). Vendors: [Cure53](https://junglewise.ai/threats/vendors/cure53), [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** Medium severity, with a CVSS score of 4, published 30 September 2026.

**Which products and versions are affected?** Cure53 DOMPurify 3.4.13 to 3.4.15; dompurify (npm) SEMVER:introduced=3.4.13,fixed=3.4.16.

**Is there a fix for This vulnerability?** Yes. dompurify (npm): upgrade to 3.4.16 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is This vulnerability attacked?** It is attacked over the network.

**Am I affected?** Check whether you run Cure53 DOMPurify or dompurify (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- dompurify (npm): upgrade to 3.4.16 or later

  ```sh
  npm install dompurify@3.4.16
  ```


## Technical details

The vulnerability occurs in DOMPurify's IN_PLACE sanitization mode when a node-removing afterSanitizeElements or afterSanitizeAttributes hook detaches non-root elements. The _handleHookDetachedNode neutralization helper is missing from the afterSanitize return paths and _sanitizeAttributes, leaving event handler attributes (on*) intact on detached subtrees. Because IN_PLACE mutates the caller's live DOM, queued event handlers on detached descendants fire in page scope after sanitize() returns, achieving DOM XSS without special privileges.

## Affected products

- Cure53 DOMPurify 3.4.13 to 3.4.15

## Timeline

- 2026-09-30: disclosed
- 2026-09-30: patched: Patched in version 3.4.16

## References

- [https://github.com/cure53/DOMPurify/security/advisories/GHSA-p98j-92pf-mc4p](https://github.com/cure53/DOMPurify/security/advisories/GHSA-p98j-92pf-mc4p)
- [https://github.com/cure53/DOMPurify/pull/1636](https://github.com/cure53/DOMPurify/pull/1636)

## Related threats

- [DOMPurify SAFE_FOR_TEMPLATES bypass via shadow root content](https://junglewise.ai/threats/cve-2026-116804-dompurify-from-3-4-4-before-3-4-17-contains-a-safe-for-templates)
- [DOMPurify DOM XSS in IN_PLACE hook-detached subtrees](https://junglewise.ai/threats/cve-2026-116803-dompurify-before-3-4-17-contains-a-cross-site-scripting)
- [DOMPurify cross-site scripting in SMIL attributeName guard bypass](https://junglewise.ai/threats/cve-2026-116802-dompurify-before-3-4-17-contains-a-cross-site-scripting)
- [DOMPurify SAFE_FOR_TEMPLATES bypass in shadow root content](https://junglewise.ai/threats/dompurify-safe-for-templates-bypass-split-template-expressions-survive-c23665cf)
- [DOMPurify IN_PLACE event handler bypass when hook removes parent or sibling](https://junglewise.ai/threats/dompurify-in-place-hook-that-removes-a-parent-or-sibling-leaves-the-3ea5d18f)