CVE-2021-26402 Memory corruption in 2nd Gen EPYC

High 7.1 Published 10 Jan 2023 Updated 8 Apr 2025

Insufficient bounds checking in AMD Secure Processor firmware allows attackers to write out-of-bounds data, compromising integrity and availability.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-26402?

CVE-2021-26402 is a high-severity memory corruption vulnerability in Amd Epyc 7232p Firmware, published on 10 Jan 2023. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

Insufficient bounds checking in ASP (AMD Secure Processor) firmware while handling BIOS mailbox commands, may allow an attacker to write partially-controlled data out-of-bounds to SMM or SEV-ES regions which may lead to a potential loss of integrity and availability.

Weakness: CWE-787

Which versions are affected by CVE-2021-26402?

It affects 50 products.

Products include Amd Epyc 7002 Firmware, Amd Epyc 7003 Firmware, Amd Epyc 7232p Firmware, Amd Epyc 7252 Firmware, Amd Epyc 7262 Firmware, Amd Epyc 7272 Firmware and 44 more.

How do I fix CVE-2021-26402?

No fix has been published for CVE-2021-26402 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2021-26402 being exploited?

There is no known exploitation of CVE-2021-26402 in the wild and no public exploit code.

All Amd Epyc 7232p Firmware vulnerabilities

Sources

Also known as GHSA-f358-f8cc-67vr.