Off-by-One Error in AMD Secure Encrypted Virtualization Firmware
CVE-2026-40669

4MEDIUM

Key Information:

Vendor

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

What is CVE-2026-40669?

An off-by-one error in the firmware of AMD's Secure Encrypted Virtualization (SEV) can allow an attacker with hypervisor access to manipulate the Reverse Map Table (RMP). This manipulation poses a serious risk to the integrity of guest memory, potentially leading to unauthorized access or data corruption. It is crucial for users to apply the latest security updates to mitigate this risk.

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™ 9004 Series Processors GenoaPI_1.0.0.J

References

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

CVSS V4

Score:
4
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Local
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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