CVE-2026-65904
DOMPurify before 3.4.4 Cross-Site Scripting via IN_PLACE mode
Description
DOMPurify through 3.3.3 fails to sanitize DOM elements passed via IN_PLACE mode when the element originates from a different window/realm (e.g., an iframe's contentDocument). A cross-realm instanceof check in the private _isNode() function returns false for foreign-realm nodes, causing DOMPurify to stringify the element (yielding '[object HTMLDivElement]'), silently reset IN_PLACE to false, and return the unsanitized element unchanged with any XSS payloads intact. The vendor considers this an edge case outside DOMPurify's threat model and, at time of publication, no fix was planned.
INFO
Published Date :
July 23, 2026, 2:18 p.m.
Last Modified :
July 23, 2026, 3:11 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 4.0 | LOW | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | LOW | [email protected] |
Solution
- Sanitize cross-realm elements as strings instead of nodes.
- Avoid DOMPurify's IN_PLACE mode for foreign realm content.
- Update DOMPurify if a fix becomes available.
- Implement strict input validation and sanitization.
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-2026-65904.
| URL | Resource |
|---|---|
| https://github.com/cure53/DOMPurify/security/advisories/GHSA-4w3q-35jp-p934 | |
| https://www.vulncheck.com/advisories/dompurify-before-cross-site-scripting-via-in-place-mode |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-65904 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-2026-65904
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).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-65904 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-65904 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.
-
New CVE Received by [email protected]
Jul. 23, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'cure53', 'product': 'DOMPurify', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '3.4.4', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '3.4.4', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/dompurify', 'defaultStatus': 'unaffected'}] Added Description DOMPurify through 3.3.3 fails to sanitize DOM elements passed via IN_PLACE mode when the element originates from a different window/realm (e.g., an iframe's contentDocument). A cross-realm instanceof check in the private _isNode() function returns false for foreign-realm nodes, causing DOMPurify to stringify the element (yielding '[object HTMLDivElement]'), silently reset IN_PLACE to false, and return the unsanitized element unchanged with any XSS payloads intact. The vendor considers this an edge case outside DOMPurify's threat model and, at time of publication, no fix was planned. Added CVSS V4.0 AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N Added CWE CWE-754 Added Reference https://github.com/cure53/DOMPurify/security/advisories/GHSA-4w3q-35jp-p934 Added Reference https://www.vulncheck.com/advisories/dompurify-before-cross-site-scripting-via-in-place-mode