AMD SMM Supervisor (AMD-SB-7011): MULTI-TENANT ISOLATION: The highest-scored AMD platform CVE in this database at 9.8

Impact

MULTI-TENANT ISOLATION: The highest-scored AMD platform CVE in this database at 9.8 critical. A flaw in the AMD SMM Supervisor - the component that is supposed to *constrain* what SMM code can do - yields full compromise of confidentiality, integrity and availability. SMM sits above the hypervisor and can reach all physical memory; owning it means owning every VM, container and confidential guest on the node, persistently and invisibly to anything running above.

Who can reach it

NVD scores this as network-reachable with no privileges required, which is unusually severe for an SMM issue and worth treating at face value until you can prove otherwise for your platform. AMD's own framing is narrower. Given the disagreement, patch first and reconcile the vector later.

What to do

Fixed in AMD PI/AGESA firmware and delivered only as an OEM SBIOS package - AMD ships the PI drop to Dell, HPE, Supermicro, Lenovo and the ODMs, who each requalify before releasing BIOS. **Budget one to six months of OEM lag**, and note that several CVEs in this batch are marked 'no fix planned' on Naples (EPYC 7001) - for those the only remediation is retiring the hardware. Applying it means cordon, drain and a full power cycle per node; there is no driver reload, no live patch and no VBIOS step. Treat as the top of your AMD firmware queue purely on score and blast radius. If your OEM has not shipped a BIOS carrying it, escalate with them rather than waiting on the normal cycle.

References