CVE-2026-19706

EUVD-2026-120121
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
8.3 HIGH
ADJACENT_NETWORK
HIGH
NONE
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Common Weakness Enumeration
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/