How severe is CVE-2021-26321?

CVE-2021-26321 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 none, integrity none, and availability high.

Is CVE-2021-26321 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-26321?

CVE-2021-26321 primarily affects Amd Epyc 7601 Firmware. In total, 57 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-26321?

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

When was CVE-2021-26321 published?

CVE-2021-26321 was published on 2021-11-16 and last updated on 2026-06-17.

CVE-2021-26321

CVE-2021-26321 is a medium-severity vulnerability in Amd Epyc 7601 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-77.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v2: 4.9
EPSS exploit prediction: 0% (15th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-77
Affected product: Amd Epyc 7601 Firmware
Published: 2021-11-16
Last modified: 2026-06-17

Description

Insufficient ID command validation in the SEV Firmware may allow a local authenticated attacker to perform a denial of service of the PSP.

Frequently asked questions

What is CVE-2021-26321?: Insufficient ID command validation in the SEV Firmware may allow a local authenticated attacker to perform a denial of service of the PSP.
How severe is CVE-2021-26321?: CVE-2021-26321 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 none, integrity none, and availability high.
Is CVE-2021-26321 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-26321?: CVE-2021-26321 primarily affects Amd Epyc 7601 Firmware. In total, 57 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-26321?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-26321 published?: CVE-2021-26321 was published on 2021-11-16 and last updated on 2026-06-17.

References

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

Affected products (57)

cpe:2.3:o:amd:epyc_7601_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7551p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7551_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7501_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7451_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7401_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7371_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7351p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7351_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7301_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7281_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7261_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7251_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7f72_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7f52_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7f32_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7h12_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7742_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7702_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7702p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7662_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7642_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7552_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7542_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7532_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7502_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7502p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7452_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7402_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7402p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7352_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7302_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7302p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7282_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7272_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7262_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7252_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7232p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7763_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7713p_firmware:*:*:*:*:*:*:*:*

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