MyBB – Privilege Escalation from Limited ACP User Management to Administrator_CVE-2026-58054

{
    "lastseen": "",
    "description": "MyBB 1.8.40 does not restrict which usergroup a limited Admin Control Panel user may assign when creating or editing users; the user module offers the Administrators group (gid 4) and its datahandler's verify_usergroup() unconditionally returns true. An admin holding only the delegated user-management permission can assign the Administrators group to an account and escalate to the full Administrator permission set.",
    "published": "2026-06-28T01:32:56.492Z",
    "modified": "2026-06-28T01:32:56.492Z",
    "type": "cve",
    "title": "MyBB - Privilege Escalation from Limited ACP User Management to Administrator",
    "source": "VulnCheck",
    "references": "https://github.com/bikini/exploitarium/tree/main/mybb-limited-acp-to-admin\nhttps://www.vulncheck.com/advisories/mybb-privilege-escalation-from-limited-acp-user-management-to-administrator",
    "id": "CVE-2026-58054",
    "bulletinFamily": "",
    "cwe": [
        "CWE-269"
    ],
    "cvelist": null,
    "sourceData": "MyBB MyBB 0",
    "sourceHref": "",
    "cvss": {
        "score": 7.2,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
        "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": "MyBB",
    "version": "0",
    "vendor": "MyBB",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}