The 9.3 CVSS on CVE-2026-71566 captures the impact, but it doesn't explain why this went undetected. FakeFish was designed with a clean mental model: credentials flow down to scripts, and validation happens at the BMC. That's a valid abstraction in bare-metal contexts where the BMC is the final arbiter. KubeVirt introduces a fundamentally different trust model by mounting a KUBECONFIG and discarding the credentials entirely — not through any explicit misconfiguration you'd notice, but by treating credential bypass as a first-class deployment pattern. FakeFish doesn't know it's being used in a context where its credential-passing mechanism has been silently abandoned; it just sees the operation succeed. This is a privilege escalation that happens at the infrastructure layer, invisible to the operator.
What makes this worth your attention isn't the CVSS number — it's the pattern. This vulnerability is the third documented expression of a recurring genotype: a tool assumes downstream validation, a composition layer introduces an alternate credential source without marking the override, and the original tool continues publishing a credential interface that no longer reflects operational reality. You can trace this in CVE-2019-10192 and CVE-2021-43287. The genotype isn't 'delegates to somebody else' — it's specifically a pattern that was valid when the delegating layer still honored the pass-through, then became vestigial without any deprecation marker or breaking change notice.
The EPSS score of 0.00212 against a 9.3 CVSS doesn't reduce the severity — it concentrates it. The actors who CAN exploit this are cluster operators, the highest-privilege users in the system, and the failure mode (unauthorized VM control with arbitrary image mounting) is a pivot point for lateral movement. The narrow exploitability isn't a comfort; it's a fingerprint pointing to exactly which deployment topologies are vulnerable.
Check your KubeVirt deployment: if you're mounting a KUBECONFIG while FakeFish is still passing credentials as a parameter, you're in the blast radius. The credentials parameter still exists, FakeFish still passes it, the operation still succeeds — but KubeVirt stopped processing it. That's the ghost contract. Verify whether your composition layer has deprecated credential-passing semantics without updating the interface contract. The fix isn't just patching FakeFish; it's updating your composition assumptions across every downstream deployment that pins specific container image SHA256s, because the remediation lag compounds through versioned images and CI pipelines that can't rebuild mid-shift.