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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Assisted Installer for Red Hat OpenShift Container Platform 2 | — | — |
| Red Hat | Multicluster Engine for Kubernetes | — | — |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — |
| Red Hat | Red Hat OpenShift Container Platform 5 | — | — |
References
- https://access.redhat.com/security/cve/CVE-2026-19706 vdb-entry
- RHBZ#2515215 issue-tracking
- 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/