Craft CMS – Missing Authorization in assets/preview-thumb Endpoint_CVE-2026-56384

{
    "lastseen": "",
    "description": "Craft CMS contains a missing authorization vulnerability in the assets/preview-thumb endpoint. A Control Panel user without permission to view a target private asset can call the endpoint with an attacker-controlled assetId and receive preview HTML containing a signed fallback transform preview link for that private asset, because no asset-view permission check is performed before preview generation. This affects versions >= 4.0.0-RC1, <= 4.17.7 and >= 5.0.0-RC1, <= 5.9.13, and is fixed in 4.17.8 and 5.9.14.",
    "published": "2026-06-21T13:27:00.378Z",
    "modified": "2026-06-21T13:27:00.378Z",
    "type": "cve",
    "title": "Craft CMS - Missing Authorization in assets/preview-thumb Endpoint",
    "source": "VulnCheck",
    "references": "https://github.com/craftcms/cms/security/advisories/GHSA-x76w-8c62-48mg\nhttps://github.com/craftcms/cms/commit/d30df3112220db1ffd6726a3ed11857014c7fb27\nhttps://www.vulncheck.com/advisories/craft-cms-missing-authorization-in-assets-preview-thumb-endpoint",
    "id": "CVE-2026-56384",
    "bulletinFamily": "",
    "cwe": [
        "CWE-862"
    ],
    "cvelist": null,
    "sourceData": "craftcms cms 4.0.0-RC1\ncraftcms cms 5.0.0-RC1",
    "sourceHref": "",
    "cvss": {
        "score": 5.3,
        "severity": "MEDIUM",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/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": "cms",
    "version": "4.0.0-RC1",
    "vendor": "craftcms",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}