CVE-2026-19706

Description

During ABI bootstrap, the bootstrap node's approve-csr.service approves and signs every CSR without identity validation. An 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. Exploitable only during the narrow bootstrap window.

References

• https://access.redhat.com/security/cve/CVE-2026-19706
• https://bugzilla.redhat.com/show_bug.cgi?id=2515215
• https://docs.redhat.com/en/documentation/openshift_container_platform/4.22/html/installing_an_on-premise_cluster_with_the_agent-based_installer/index
• https://kubernetes.io/docs/reference/access-authn-authz/certificate-signing-requests/