{"id":"CVE-2026-4740","revision":"ac487af6bbe44af8a56b39c11b520ddd","records":[{"revision":"ac487af6bbe44af8a56b39c11b520ddd","observedAt":"2026-10-27T13:11:48.565+00:00","statement":{"source":"nvd","id":"CVE-2026-4740","aliases":[],"title":"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 ce…","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.","state":0,"publishedAt":"2026-04-07T15:17:46.797+00:00","modifiedAt":"2026-10-26T21:10:00.17+00:00","affected":[],"metrics":[{"system":"CVSS 3.1 · secalert@redhat.com · Secondary","vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","score":8.2,"severity":"HIGH"},{"system":"CVSS 3.1 · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c · Secondary","vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","score":8.2,"severity":"HIGH"}],"references":["https://access.redhat.com/errata/RHSA-2026:11414","https://access.redhat.com/errata/RHSA-2026:13542","https://access.redhat.com/errata/RHSA-2026:13853","https://access.redhat.com/errata/RHSA-2026:8218","https://access.redhat.com/errata/RHSA-2026:9848","https://access.redhat.com/security/cve/CVE-2026-4740","https://blog.arfevrier.fr/open-cluster-management-cross-cluster-escape/","https://bugzilla.redhat.com/show_bug.cgi?id=2450590","https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4740.json"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-4740","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Modified","weaknesses":["CWE-295"],"productCriteria":["cpe:2.3:a:redhat:advanced_cluster_management_for_kubernetes:-:*:*:*:*:*:*:*"],"sourceDates":{"published":"2026-04-07T15:17:46.797","lastModified":"2026-10-26T21:10:00.170"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-4740","identifiers":["CVE-2026-4740"]},"retained":false,"historicalAffected":[]}],"coverage":[]}