CVE-2026-41240 — Cross-site Scripting in Dompurify

CWE-79 — Cross-site ScriptingCWE-183 — Permissive List of Allowed Inputs9 documents5 sources
Severity
6.0MEDIUMNVD
EPSS
0.1%
top 81.85%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
45
Cure53 Dompurify3scale-amp2 System-rhel73scale-amp2 System-rhel8+42 more
Timeline
PublishedApr 23
Latest updateApr 28

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 …

CVSS vector

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

Affected Packages47 packages

▶CVEListV5cure53/dompurify< 3.4.0
▶npmcure53/dompurify< 3.4.0

🔴Vulnerability Details

2
VulDB
cure53 DOMPurify up to 3.3.x permissive list of allowed inputs↗2026-04-23
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GHSA
DOMPurify: FORBID_TAGS bypassed by function-based ADD_TAGS predicate (asymmetry with FORBID_ATTR fix)↗2026-04-22
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📋Vendor Advisories

1
Red Hat
DOMPurify: DOMPurify: Cross-Site Scripting (XSS) via inconsistent tag sanitization↗2026-04-23
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💬Community

5
Bugzilla
CVE-2026-41240 nodejs-aw-webui: DOMPurify: Cross-Site Scripting (XSS) via inconsistent tag sanitization [fedora-all]↗2026-04-28
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Bugzilla
CVE-2026-41240 python-jupytext: DOMPurify: Cross-Site Scripting (XSS) via inconsistent tag sanitization [fedora-all]↗2026-04-28
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Bugzilla
CVE-2026-41240 openbao: DOMPurify: Cross-Site Scripting (XSS) via inconsistent tag sanitization [fedora-all]↗2026-04-28
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Bugzilla
CVE-2026-41240 openbao: DOMPurify: Cross-Site Scripting (XSS) via inconsistent tag sanitization [epel-all]↗2026-04-28
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Bugzilla
CVE-2026-41240 DOMPurify: DOMPurify: Cross-Site Scripting (XSS) via inconsistent tag sanitization↗2026-04-23
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