Concrete CMS below 9.5.2 is vulnerable to PHP Object Injection via unserialize() calls in the Workflow, Form block, and File/Set components that lack the allowed_classes restriction._CVE-2026-7888

{
    "lastseen": "",
    "description": "Concrete CMS below 9.5.2 is vulnerable to PHP Object Injection via unserialize() calls in the Workflow, Form block, and File/Set components that lack the allowed_classes restriction. An unauthenticated attacker may trigger arbitrary PHP object instantiation if a malicious serialized payload has been placed in the database. Thanks XananasX7 and\u00a0Sanjorn Keeratirungsan\u00a0(dizconnect) for both independently reporting. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 8.4 with vector CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N.",
    "published": "2026-06-03T18:10:10.917Z",
    "modified": "2026-06-03T18:10:10.917Z",
    "type": "cve",
    "title": "Concrete CMS below 9.5.2 is vulnerable to PHP Object Injection via unserialize() calls in the Workflow, Form block, and File/Set components that lack the allowed_classes restriction.",
    "source": "ConcreteCMS",
    "references": "https://documentation.concretecms.org/9-x/developers/introduction/version-history/952-release-notes",
    "id": "CVE-2026-7888",
    "bulletinFamily": "",
    "cwe": [
        "CWE-502"
    ],
    "cvelist": null,
    "sourceData": "Concrete CMS Concrete CMS 5.0",
    "sourceHref": "",
    "cvss": {
        "score": 8.4,
        "severity": "HIGH",
        "vector": "CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
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        "baseScore": 0,
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        "confidentialityImpact": "",
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        "availabilityImpact": "",
        "cvssV3": {
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    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Concrete CMS",
    "version": "5.0",
    "vendor": "Concrete CMS",
    "ai_description": "",
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    "ai_score": 0
}