DOMPurify before 3.4.11 fails to clone the ALLOWED_ATTR allowlist when setConfig() is used with an uponSanitizeAttribute hook, allowing the hook to permanently mutate the shared allowlist. Attackers can register a hook that conditionally allows dangerous attributes like onerror for trusted elements, then submit untrusted content that inherits the polluted allowlist and executes event handlers as stored XSS.

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-cmwh-pvxp-8882 DOMPurify: Permanent `ALLOWED_ATTR` pollution via `setConfig()` bypassing the hook clone-guard (incomplete fix of the 3.4.7 hook-pollution patch)
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 23 Jul 2026 13:30:00 +0000

Type Values Removed Values Added
Description DOMPurify before 3.4.11 fails to clone the ALLOWED_ATTR allowlist when setConfig() is used with an uponSanitizeAttribute hook, allowing the hook to permanently mutate the shared allowlist. Attackers can register a hook that conditionally allows dangerous attributes like onerror for trusted elements, then submit untrusted content that inherits the polluted allowlist and executes event handlers as stored XSS.
Title DOMPurify before 3.4.11 Permanent Attribute Allowlist Pollution via setConfig
First Time appeared Cure53
Cure53 dompurify
Weaknesses CWE-79
CPEs cpe:2.3:a:cure53:dompurify:*:*:*:*:*:*:*:*
Vendors & Products Cure53
Cure53 dompurify
References
Metrics cvssV3_1

{'score': 7.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N'}

cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-07-23T13:16:17.715Z

Reserved: 2026-07-23T11:03:13.092Z

Link: CVE-2026-65898

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses