CVE-2026-49458
DOMPurify: Cross-realm IN_PLACE sanitization leaves executable markup intact via realm-bound `instanceof` checks
Description
DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.6, DOMPurify.sanitize(node, { IN_PLACE: true }) accepted same-origin foreign-realm DOM nodes while follow-on checks used parent-realm constructors, causing instanceof checks for forms, named node maps, document fragments, and elements to fail and skip clobber, template-content, and shadow-DOM sanitization branches so executable markup could survive. This issue is fixed in version 3.4.6.
INFO
Published Date :
July 14, 2026, 9:17 p.m.
Last Modified :
July 21, 2026, 7:47 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update DOMPurify library to version 3.4.6 or newer.
- Ensure proper sanitization of DOM nodes.
- Review cross-origin resource handling.
- Test application for XSS vulnerabilities.
Public PoC/Exploit Available at Github
CVE-2026-49458 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-49458.
| URL | Resource |
|---|---|
| https://github.com/cure53/DOMPurify/commit/bb7739e5bccec7e1ab3dae3f3e42d02db3acaaae | Patch |
| https://github.com/cure53/DOMPurify/releases/tag/3.4.6 | Release Notes |
| https://github.com/cure53/DOMPurify/security/advisories/GHSA-hpcv-96wg-7vj8 | Exploit Mitigation Vendor Advisory |
| https://github.com/cure53/DOMPurify/security/advisories/GHSA-hpcv-96wg-7vj8 | Exploit Mitigation Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-49458 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-49458
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Dockerfile
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-49458 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-49458 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jul. 21, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:cure53:dompurify:*:*:*:*:*:*:*:* versions up to (excluding) 3.4.6 Added Reference Type GitHub, Inc.: https://github.com/cure53/DOMPurify/commit/bb7739e5bccec7e1ab3dae3f3e42d02db3acaaae Types: Patch Added Reference Type GitHub, Inc.: https://github.com/cure53/DOMPurify/releases/tag/3.4.6 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/cure53/DOMPurify/security/advisories/GHSA-hpcv-96wg-7vj8 Types: Exploit, Mitigation, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/cure53/DOMPurify/security/advisories/GHSA-hpcv-96wg-7vj8 Types: Exploit, Mitigation, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 15, 2026
Action Type Old Value New Value Added Reference https://github.com/cure53/DOMPurify/security/advisories/GHSA-hpcv-96wg-7vj8 Added SSVC {'id': 'CVE-2026-49458', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-15T13:02:56.040047Z'} -
New CVE Received by [email protected]
Jul. 14, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'cure53', 'product': 'DOMPurify', 'versions': [{'status': 'affected', 'version': '< 3.4.6'}]}] Added Description DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.6, DOMPurify.sanitize(node, { IN_PLACE: true }) accepted same-origin foreign-realm DOM nodes while follow-on checks used parent-realm constructors, causing instanceof checks for forms, named node maps, document fragments, and elements to fail and skip clobber, template-content, and shadow-DOM sanitization branches so executable markup could survive. This issue is fixed in version 3.4.6. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Added CWE CWE-79 Added CWE CWE-693 Added CWE CWE-501 Added Reference https://github.com/cure53/DOMPurify/commit/bb7739e5bccec7e1ab3dae3f3e42d02db3acaaae Added Reference https://github.com/cure53/DOMPurify/releases/tag/3.4.6 Added Reference https://github.com/cure53/DOMPurify/security/advisories/GHSA-hpcv-96wg-7vj8