CVE-2021-26331

HighCVSS 7.8/10Last modified Jun 17, 2026

Description

AMD System Management Unit (SMU) contains a potential issue where a malicious user may be able to manipulate mailbox entries leading to arbitrary code execution.

Metrics

CVSS 3.1 7.8/10CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness enumeration

CWE-20

Affected software

Vendor	Product	Versions
AMD	1st Gen AMD EPYC™	>= unspecified, < NaplesPI-SP3_1.0.0.G
AMD	2nd Gen AMD EPYC™	>= unspecified, < RomePI-SP3_1.0.0.C
AMD	3rd Gen AMD EPYC™	>= unspecified, < MilanPI-SP3_1.0.0.4

References

https://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1021Vendor Advisory
https://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1021Vendor Advisory

Timeline

Published: Nov 16, 2021
Last modified: Jun 17, 2026
NVD status: Modified

Related CVEs from 2021

CVE-2021-263327.1Failure to verify SEV-ES TMR is not in MMIO space, SEV-ES FW could result in a potential loss of integrity or availability.CVE-2021-263335.5An information disclosure vulnerability exists in AMD Platform Security Processor (PSP) chipset driver. The discretionary access control lis CVE-2021-263349.9The AMDPowerProfiler.sys driver of AMD μProf tool may allow lower privileged users to access MSRs in kernel which may lead to privilege esca CVE-2021-263357.8Improper input and range checking in the AMD Secure Processor (ASP) boot loader image header may allow an attacker to use attacker-controlle CVE-2021-263365.5Insufficient bounds checking in System Management Unit (SMU) may cause invalid memory accesses/updates that could result in SMU hang and sub CVE-2021-263375.5Insufficient DRAM address validation in System Management Unit (SMU) may result in a DMA read from invalid DRAM address to SRAM resulting in CVE-2021-263387.5Improper access controls in System Management Unit (SMU) may allow for an attacker to override performance control tables located in DRAM re CVE-2021-263395.5A bug in AMD CPU’s core logic may allow for an attacker, using specific code from an unprivileged VM, to trigger a CPU core hang resulting i CVE-2021-263408.4A malicious hypervisor in conjunction with an unprivileged attacker process inside an SEV/SEV-ES guest VM may fail to flush the Translation CVE-2021-263416.5Some AMD CPUs may transiently execute beyond unconditional direct branches, which may potentially result in data leakage.CVE-2021-263423.3In SEV guest VMs, the CPU may fail to flush the Translation Lookaside Buffer (TLB) following a particular sequence of operations that includ CVE-2021-263435.5Insufficient validation in ASP BIOS and DRTM commands may allow malicious supervisor x86 software to disclose the contents of sensitive memo