DOMPurify: FORBID_TAGS bypassed by function-based ADD_TAGS predicate (asymmetry with FORBID_ATTR fix)_CVE-2026-41240

{
    "lastseen": "",
    "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.",
    "published": "2026-04-23T14:54:32.426Z",
    "modified": "2026-04-23T14:54:32.426Z",
    "type": "cve",
    "title": "DOMPurify: FORBID_TAGS bypassed by function-based ADD_TAGS predicate (asymmetry with FORBID_ATTR fix)",
    "source": "GitHub_M",
    "references": "https://github.com/cure53/DOMPurify/security/advisories/GHSA-h7mw-gpvr-xq4m\nhttps://github.com/cure53/DOMPurify/commit/c361baa18dbdcb3344a41110f4c48ad85bf48f80\nhttps://github.com/cure53/DOMPurify/releases/tag/3.4.0",
    "id": "CVE-2026-41240",
    "bulletinFamily": "",
    "cwe": [
        "CWE-183",
        "CWE-79"
    ],
    "cvelist": null,
    "sourceData": "cure53 DOMPurify < 3.4.0",
    "sourceHref": "",
    "cvss": {
        "score": 6,
        "severity": "MEDIUM",
        "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",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "DOMPurify",
    "version": "< 3.4.0",
    "vendor": "cure53",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}