← Vulnerability feed

Vulnerability record · CVE-2021-26356 · published 9 May 2023

CVE-2021-26356: Amd epyc 7001 firmware toctou race condition vulnerability

AAmd · Epyc 7001 Firmware

A TOCTOU in ASP bootloader may allow an attacker to tamper with the SPI ROM following data read to memory potentially resulting in S3 data corruption and information disclosure.

7.4 CVSS 3.1 High EPSS 0.40% · top 68.4% CWE-367 · TOCTOU race condition
7.4CVSS 3.1 base score
0.40%EPSS exploitation probability, 30 days
NoNot in CISA KEV
98Affected product versions listed by NVD
4References
17 Jun 2026Last modified by NVD

Description

A TOCTOU in ASP bootloader may allow an attacker to tamper with the SPI ROM following data read to memory potentially resulting in S3 data corruption and information disclosure.

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

Affected products

98 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-3001 Vendor Advisory
https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-4001 Vendor Advisory
https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-3001 Vendor Advisory
https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-4001 Vendor Advisory

Track CVE-2021-26356 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2023-20520Amd epyc 72f3 firmware out-of-bounds write vulnerabilityImproper access control settings in ASP Bootloader may allow an attacker to corrupt the return address causing a stack-based buffer overrun potential…EPSS 0.79%9.8CVE-2021-26379Amd epyc 72f3 firmware vulnerabilityInsufficient input validation of mailbox data in the SMU may allow an attacker to coerce the SMU to corrupt SMRAM, potentially leading to a loss of i…EPSS 0.68%9.1CVE-2021-46756Amd epyc 72f3 firmware improper input validation vulnerabilityInsufficient validation of inputs in SVC_MAP_USER_STACK in the ASP (AMD Secure Processor) bootloader may allow an attacker with a malicious Uapp or A…EPSS 0.65%9.1CVE-2021-46762Amd epyc 72f3 firmware improper input validation vulnerabilityInsufficient input validation in the SMU may allow an attacker to corrupt SMU SRAM potentially leading to a loss of integrity or denial of service.EPSS 0.35%8.8CVE-2021-46769Amd epyc 72f3 firmware improper input validation vulnerabilityInsufficient syscall input validation in the ASP Bootloader may allow a privileged attacker to execute arbitrary DMA copies, which can lead to code e…EPSS 0.78%8.4CVE-2021-26340Amd epyc 7001 firmware vulnerabilityA malicious hypervisor in conjunction with an unprivileged attacker process inside an SEV/SEV-ES guest VM may fail to flush the Translation Lookaside…EPSS 0.24%8.2CVE-2021-26344Amd epyc 7203 firmware out-of-bounds write vulnerabilityAn out of bounds memory write when processing the AMD PSP1 Configuration Block (APCB) could allow an attacker with access the ability to modify the B…EPSS 0.16%7.8CVE-2021-26398Amd epyc 7h12 firmware out-of-bounds write vulnerabilityInsufficient input validation in SYS_KEY_DERIVE system call in a compromised user application or ABL may allow an attacker to corrupt ASP (AMD Secure…EPSS 0.21%

Source: NIST National Vulnerability Database (record CVE-2021-26356), CISA KEV, FIRST EPSS (scores of 2026-09-30). This page is refreshed as NVD updates the record.