# CVE-2026-65912: cure53 DOMPurify URI validation bypass in attributeCheck

Source: https://junglewise.ai/threats/cve-2026-65912-cure53-dompurify-uri-validation-bypass-in-attributecheck  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-23. Updated: 2026-07-23  
License: CC BY 4.0 with a link back

CVE-2026-65912 · Severity: medium · CVSS 6.1 · Published 2026-07-23

DOMPurify, a widely used library for cleaning HTML to prevent security attacks, contains a flaw in how it validates web links. If a developer configures the library with specific custom rules, an attacker can bypass security filters to include malicious 'javascript:' links. If a user clicks one of these links, it could allow the attacker to steal data or perform unauthorized actions in the user's browser session.

Technologies: [dompurify (npm)](https://junglewise.ai/threats/technologies/dompurify). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-65912 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-65912 being exploited in the wild.

**How severe is CVE-2026-65912?** Medium severity, with a CVSS score of 6.1, published 23 July 2026.

**Which products and versions are affected?** dompurify (npm) <= 3.3.1, SEMVER:introduced=0,fixed=3.3.2.

**Is there a fix for CVE-2026-65912?** Yes. dompurify (npm): upgrade to 3.3.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-65912 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-65912?** Check whether you run 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 3.3.2 or later

  ```sh
  npm install dompurify@3.3.2
  ```


## Technical details

A vulnerability exists in DOMPurify's _isValidAttribute function when using the EXTRA_ELEMENT_HANDLING.attributeCheck configuration. When a predicate function is provided via ADD_ATTR and returns true, the library short-circuits the attribute validation process, skipping subsequent URI-safe protocol checks. This allows malicious protocols such as 'javascript:' to bypass the sanitizer. An attacker can exploit this to execute DOM-based Cross-Site Scripting (XSS) if they can influence the input being sanitized and the victim interacts with the resulting malicious element (e.g., clicking a link). The issue is resolved in version 3.3.2.

## Affected products

- cure53 DOMPurify < 3.3.2

## Identifiers

- CVE-2026-65912
- GHSA-cjmm-f4jc-qw8r

## Timeline

- 2026-04-01: advisory: GHSA-cjmm-f4jc-qw8r published by cure53
- 2026-07-23: disclosed: CVE-2026-65912 published to NVD
- 2026-07-23: patched: Fix confirmed in version 3.3.2

## References

- [https://github.com/cure53/DOMPurify/security/advisories/GHSA-cjmm-f4jc-qw8r](https://github.com/cure53/DOMPurify/security/advisories/GHSA-cjmm-f4jc-qw8r)
- [https://www.vulncheck.com/advisories/dompurify-before-uri-validation-bypass-via-add-attr](https://www.vulncheck.com/advisories/dompurify-before-uri-validation-bypass-via-add-attr)

## Related threats

- [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)
- [DOMPurify SMIL attributeName=href guard bypass in XHTML mode](https://junglewise.ai/threats/dompurify-smil-attributename-href-guard-is-skipped-when-parser-media-15a5efd2)
- [DOMPurify IN_PLACE mode XSS via rawtext element text content](https://junglewise.ai/threats/dompurify-in-place-returns-a-force-removed-rawtext-root-whose-text-16d9ac9e)
- [DOMPurify DOM XSS in IN_PLACE mode with afterSanitize hooks](https://junglewise.ai/threats/dompurify-in-place-node-removing-aftersanitize-hook-leaves-detached-3087e7fd)