How severe is CVE-2021-26404?

CVE-2021-26404 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-26404 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-26404?

CVE-2021-26404 primarily affects Amd Epyc 7003 Firmware. In total, 23 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-26404?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-26404 published?

CVE-2021-26404 was published on 2023-01-11 and last updated on 2026-06-17.

CVE-2021-26404

CVE-2021-26404 is a medium-severity vulnerability in Amd Epyc 7003 Firmware with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (8th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Amd Epyc 7003 Firmware
Published: 2023-01-11
Last modified: 2026-06-17

Description

Improper input validation and bounds checking in SEV firmware may leak scratch buffer bytes leading to potential information disclosure.

Frequently asked questions

What is CVE-2021-26404?: Improper input validation and bounds checking in SEV firmware may leak scratch buffer bytes leading to potential information disclosure.
How severe is CVE-2021-26404?: CVE-2021-26404 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-26404 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-26404?: CVE-2021-26404 primarily affects Amd Epyc 7003 Firmware. In total, 23 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-26404?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-26404 published?: CVE-2021-26404 was published on 2023-01-11 and last updated on 2026-06-17.

References

https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-1032

Affected products (23)

cpe:2.3:o:amd:epyc_7003_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7313_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7313p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7343_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7373x_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_73f3_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7413_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7443_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7443p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7453_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7473x_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_74f3_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7513_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7543_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7543p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7573x_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7643_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_75f3_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7663_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7713_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7713p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7763_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7773x_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Amd Epyc 7003 Firmware

CVE-2021-26398 — High (CVSS 7.8): Insufficient input validation in SYS_KEY_DERIVE system call in a compromised user application or ABL may allow an…
CVE-2021-26316 — High (CVSS 7.8): Failure to validate the communication buffer and communication service in the BIOS may allow an attacker to tamper with…
CVE-2021-26335 — High (CVSS 7.8): Improper input and range checking in the AMD Secure Processor (ASP) boot loader image header may allow an attacker to…
CVE-2021-26331 — High (CVSS 7.8): AMD System Management Unit (SMU) contains a potential issue where a malicious user may be able to manipulate mailbox…
CVE-2021-26315 — High (CVSS 7.8): When the AMD Platform Security Processor (PSP) boot rom loads, authenticates, and subsequently decrypts an encrypted…
CVE-2020-12961 — High (CVSS 7.8): A potential vulnerability exists in AMD Platform Security Processor (PSP) that may allow an attacker to zero any…

All CVEs affecting Amd Epyc 7003 Firmware →

Other CWE-20 (Improper Input Validation) vulnerabilities

CVE-2026-48316 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48281 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48277 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48055 — Critical (CVSS 10.0): Streambert is a cross-platform Electron Desktop App to stream and download any video media. In versions 2.4.0 and…
CVE-2026-34910 — Critical (CVSS 10.0): A malicious actor with access to the network could exploit an Improper Input Validation vulnerability found in UniFi OS…
CVE-2026-33587 — Critical (CVSS 10.0): Lack of user input sanitisation in Open Notebook v1.8.3 allows the application user to execute Python code (and…

Browse all CWE-20 (Improper Input Validation) vulnerabilities →