Apache CloudStack: Proxmox Extension Allows Unauthorized Cross-Tenant Instance Access_CVE-2026-25199

{
    "lastseen": "",
    "description": "Instances deployed via the Proxmox extension allow unauthorized access to instances belonging to other tenants.\n\n\n\n\nThis issue affects Apache CloudStack: from 4.21.0.0 through 4.22.0.0.\n\n\n\n\nThe Proxmox extension for CloudStack improperly uses a user-editable instance setting, proxmox_vmid, to associate CloudStack instances with Proxmox virtual machines. Because this value is not restricted or validated against tenant ownership and Proxmox VM IDs are predictable, a non-privileged attacker can modify the setting to reference a VM belonging to another account. This allows unauthorized cross-tenant access and enables full control over the targeted VM, including starting, stopping, and destroying the virtual machine.\n\n\n\n\nUsers are recommended to upgrade to version 4.22.0.1, which fixes this issue.\n\n\n\n\nAs a workaround for the existing installations, editing of the proxmox_vmid instance detail by users can be prevented by adding this detail name to the global configuration parameter - user.vm.denied.details.",
    "published": "2026-05-08T12:22:56.226Z",
    "modified": "2026-05-08T17:46:13.532Z",
    "type": "cve",
    "title": "Apache CloudStack: Proxmox Extension Allows Unauthorized Cross-Tenant Instance Access",
    "source": "apache",
    "references": "https://lists.apache.org/thread/n8mt5b7wkpysstb8w7rr9f02kc5cq2xm",
    "id": "CVE-2026-25199",
    "bulletinFamily": "",
    "cwe": [
        "CWE-200"
    ],
    "cvelist": null,
    "sourceData": "Apache Software Foundation Apache CloudStack 4.21.0",
    "sourceHref": "",
    "cvss": {
        "score": 9.1,
        "severity": "CRITICAL",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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": "Apache CloudStack",
    "version": "4.21.0",
    "vendor": "Apache Software Foundation",
    "ai_description": "The Proxmox extension for CloudStack improperly uses a user-editable instance setting, allowing unauthorized cross-tenant access to instances.",
    "ai_severity": "Critical",
    "ai_vendor": "Apache Software Foundation",
    "ai_product": "Apache CloudStack",
    "ai_version": "4.21.0.0, 4.22.0.0",
    "ai_score": 9.1
}