Rhacm: open cluster management (ocm): cross-cluster privilege escalation via improper kubernetes client certificate renewal validation_CVE-2026-4740

{
    "lastseen": "",
    "description": "A flaw was found in Open Cluster Management (OCM), the technology underlying Red Hat Advanced Cluster Management (ACM). Improper validation of Kubernetes client certificate renewal allows a managed cluster administrator to forge a client certificate that can be approved by the OCM controller. This enables cross-cluster privilege escalation and may allow an attacker to gain control over other managed clusters, including the hub cluster.",
    "published": "2026-04-07T14:30:36.396Z",
    "modified": "2026-04-09T14:40:43.580Z",
    "type": "cve",
    "title": "Rhacm: open cluster management (ocm): cross-cluster privilege escalation via improper kubernetes client certificate renewal validation",
    "source": "redhat",
    "references": "https://access.redhat.com/security/cve/CVE-2026-4740\nhttps://blog.arfevrier.fr/open-cluster-management-cross-cluster-escape/\nhttps://bugzilla.redhat.com/show_bug.cgi?id=2450590",
    "id": "CVE-2026-4740",
    "bulletinFamily": "",
    "cwe": [
        "CWE-295"
    ],
    "cvelist": null,
    "sourceData": "",
    "sourceHref": "",
    "cvss": {
        "score": 8.2,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H",
        "version": "3.1"
    },
    "cvss2": [],
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        "baseScore": 0,
        "baseSeverity": "",
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        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Multicluster Engine for Kubernetes",
    "version": "",
    "vendor": "Red Hat",
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    "ai_score": 0
}