Authentication Bypass Vulnerability in AMD Secure Encrypted Virtualization Firmware
CVE-2026-40668

4.6MEDIUM

Key Information:

Vendor

Amd
Status
Amd Epyc™ 9004 Series Processors
Amd Epyc™ 7003 Series Processors
Amd Epyc™ 9005 Series Processors
Amd Epyc™ 8004 Series Processors
Vendor
CVE Published:
10 November 2026

What is CVE-2026-40668?

The vulnerability in AMD Secure Encrypted Virtualization (SEV) firmware allows a malicious hypervisor to perform authentication bypass via spoofing. This weakness enables unauthorized requests for attestation reports for VMPL 0, potentially compromising virtual machine security and enabling attackers to exploit sensitive data.

Affected Version(s)

AMD EPYC™ 7003 Series Processors MilanPI-SP3_1.0.0.K

AMD EPYC™ 8004 Series Processors GenoaPI_1.0.0.J

AMD EPYC™ 8005 Series Processors TurinPI_1.0.0.B

References

https://www.amd.com/en/resources/product-security/bulleti...

CVSS V4

Score:
4.6
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Local
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.