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Vulnerability record · CVE-2026-41240 · published 23 April 2026

CVE-2026-41240: Cure53 dompurify cross-site scripting vulnerability

Cure53 · Dompurify

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Versions prior to 3.4.0 have an inconsistency between FORBID_TAGS and FORBID_ATTR handling when function-based ADD_TAGS is used. Commit c361baa added an early exit for FORBID_ATTR at line 1214. The same fix was not applied to FORBID_TAGS. At line 1118-1123, when EXTRA_ELEMENT_HANDLING.tagCheck returns true, the short-circuit evaluation skips the FORBID_TAGS check entirely. This allows forbidden elements to survive sanitization with their attributes intact. Version 3.4.0 patches the issue.

6.0 CVSS 4.0 Medium EPSS 0.40% · top 67.9% CWE-79 · Cross-site scriptingCWE-183 · CWE-183
6.0CVSS 4.0 base score
0.40%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Versions prior to 3.4.0 have an inconsistency between FORBID_TAGS and FORBID_ATTR handling when function-based ADD_TAGS is used. Commit c361baa added an early exit for FORBID_ATTR at line 1214. The same fix was not applied to FORBID_TAGS. At line 1118-1123, when EXTRA_ELEMENT_HANDLING.tagCheck returns true, the short-circuit evaluation skips the FORBID_TAGS check entirely. This allows forbidden elements to survive sanitization with their attributes intact. Version 3.4.0 patches the issue.

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/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:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/cure53/DOMPurify/commit/c361baa18dbdcb3344a41110f4c48ad85bf48f80 Patch
https://github.com/cure53/DOMPurify/releases/tag/3.4.0 ProductRelease Notes
https://github.com/cure53/DOMPurify/security/advisories/GHSA-h7mw-gpvr-xq4m ExploitMitigationPatchVendor Advisory
https://github.com/cure53/DOMPurify/security/advisories/GHSA-h7mw-gpvr-xq4m ExploitMitigationPatchVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2024-48910Cure53 dompurify prototype pollution vulnerabilityDOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMPurify was vulnerable to prototype pollution. This vuln…EPSS 1.2%8.2CVE-2026-47423Cure53 dompurify cross-site scripting vulnerabilityDOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. In 3.4.4, DOMPurify allowed selectedcontent by default, allowing br…EPSS 0.41%6.3CVE-2026-49978Cure53 dompurify cross-site scripting vulnerabilityDOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.7, DOMPurify IN_PLACE sanitization could skip shadow c…EPSS 0.40%6.1CVE-2026-49458Cure53 dompurify cross-site scripting vulnerabilityDOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.6, DOMPurify.sanitize(node, { IN_PLACE: true }) accept…EPSS 0.40%6.1CVE-2026-49459Cure53 dompurify cross-site scripting vulnerabilityDOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.6, DOMPurify.sanitize(root, { IN_PLACE: true }) could …EPSS 0.37%6.1CVE-2025-26791Cure53 dompurify cross-site scripting vulnerabilityDOMPurify before 3.2.4 has an incorrect template literal regular expression, sometimes leading to mutation cross-site scripting (mXSS).EPSS 0.61%6.1CVE-2024-47875Cure53 dompurify cross-site scripting vulnerabilityDOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to nesting-based mXSS. This vulne…EPSS 1.1%6.1CVE-2024-45801Cure53 dompurify inefficient regular expression (redos) vulnerabilityDOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. It has been discovered that malicious HTML using special n…EPSS 0.89%

Source: NIST National Vulnerability Database (record CVE-2026-41240), CISA KEV, FIRST EPSS (scores of 2026-09-29). This page is refreshed as NVD updates the record.