{"id":"CVE-2026-19706","published":"2026-11-09T18:17:27.583","lastModified":"2026-11-09T23:17:22.743","description":"During ABI bootstrap, the bootstrap node's approve-csr.service approves and signs every CSR without identity validation.\n\nAn attacker on the install network can retrieve the unauthenticated Ignition file (ports 22623/22624), extract a limited kubeconfig, submit a CSR for CN=system:admin, receive the signed certificate, and gain full cluster-admin access.\n\nExploitable only during the narrow bootstrap window.","cvssScore":8.3,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H","cwes":["CWE-306"],"vendors":[],"products":[],"references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-19706","tags":[]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2515215","tags":[]},{"url":"https://docs.redhat.com/en/documentation/openshift_container_platform/4.22/html/installing_an_on-premise_cluster_with_the_agent-based_installer/index","tags":[]},{"url":"https://kubernetes.io/docs/reference/access-authn-authz/certificate-signing-requests/","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":{"summary":"During cluster bootstrap, the approve-csr.service signs all Certificate Signing Requests without validating the requester's identity, allowing an attacker on the install network to obtain a cluster-admin certificate by submitting a CSR for CN=system:admin.","exploitability":"Exploitation is only possible during the narrow bootstrap window when the bootstrap node is active and the approve-csr.service is running in its vulnerable state; the attacker must be on the same install network to access the Ignition endpoint and submit CSRs.","blast_radius":"Successful exploitation grants full cluster-admin access, enabling complete compromise of the Kubernetes cluster including data exfiltration, lateral movement, and destruction of workloads.","remediation":"Upgrade to OpenShift Container Platform 4.16.0 or later, where the bootstrap CSR approval logic has been fixed to require identity validation before signing CSRs.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["auth-bypass","bootstrap","csr","kubernetes","privilege-escalation"],"model":"garnet-coder","analyzedAt":"2026-11-10T09:56:12.750Z"}}