How severe is CVE-2021-26403?

CVE-2021-26403 has a CVSS 3.x base score of 6.5, 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-2021-26403 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-26403?

CVE-2021-26403 primarily affects Amd Epyc 7001 Firmware. In total, 41 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-26403?

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

When was CVE-2021-26403 published?

CVE-2021-26403 was published on 2023-01-11 and last updated on 2026-06-17.

CVE-2021-26403

CVE-2021-26403 is a medium-severity vulnerability in Amd Epyc 7001 Firmware with a CVSS 3.x base score of 6.5. 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-345.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 0% (2nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-345
Affected product: Amd Epyc 7001 Firmware
Published: 2023-01-11
Last modified: 2026-06-17

Description

Insufficient checks in SEV may lead to a malicious hypervisor disclosing the launch secret potentially resulting in compromise of VM confidentiality.

Frequently asked questions

What is CVE-2021-26403?: Insufficient checks in SEV may lead to a malicious hypervisor disclosing the launch secret potentially resulting in compromise of VM confidentiality.
How severe is CVE-2021-26403?: CVE-2021-26403 has a CVSS 3.x base score of 6.5, 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-2021-26403 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-26403?: CVE-2021-26403 primarily affects Amd Epyc 7001 Firmware. In total, 41 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-26403?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-26403 published?: CVE-2021-26403 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 (41)

cpe:2.3:o:amd:epyc_7001_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7251_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7261_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7281_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7301_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7351_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7351p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7371_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7401_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7401p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7451_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7501_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7551_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7551p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7601_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7002_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7232p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7252_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7262_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7272_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7282_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7302_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7302p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7352_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7402_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7402p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7452_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7502_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7502p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7532_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7542_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7552_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7642_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7662_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7702_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7702p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7742_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7f32_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7f52_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7f72_firmware:*:*:*:*:*:*:*:*

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