sanitize-html has an incomplete URI scheme validation that allows javascript: URIs through action, formaction, data, poster, and background attributes_CVE-2026-53606

{
    "lastseen": "",
    "description": "ApostropheCMS is an open-source Node.js content management system, and sanitize-html provides a simple HTML sanitizer with a clear API. Versions of sanitize-html prior to 2.17.5 use `allowedSchemesAppliedToAttributes` (default: `['href', 'src', 'cite']`) to gate the `naughtyHref()` function that blocks dangerous URI schemes like `javascript:` and `vbscript:`. The HTML specification defines 10+ attributes that accept URIs (`action`, `formaction`, `data`, `poster`, `background`, `ping`, `xlink:href`, `dynsrc`, `lowsrc`), but none of these are included in the default gate list. When a developer allows any of these attributes in their configuration, `javascript:` URIs pass through completely unmodified, enabling XSS. Version 2.17.5 patches the issue.",
    "published": "2026-06-12T20:50:47.085Z",
    "modified": "2026-06-12T20:50:47.085Z",
    "type": "cve",
    "title": "sanitize-html has an incomplete URI scheme validation that allows javascript: URIs through action, formaction, data, poster, and background attributes",
    "source": "GitHub_M",
    "references": "https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-vccv-cmxp-4j9h",
    "id": "CVE-2026-53606",
    "bulletinFamily": "",
    "cwe": [
        "CWE-79"
    ],
    "cvelist": null,
    "sourceData": "apostrophecms sanitize-html < 2.17.5",
    "sourceHref": "",
    "cvss": {
        "score": 5.4,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N",
        "version": "3.1"
    },
    "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": "sanitize-html",
    "version": "< 2.17.5",
    "vendor": "apostrophecms",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}