How severe is CVE-2021-26328?

CVE-2021-26328 has a CVSS 3.x base score of 4.4, 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 low, and availability low.

Is CVE-2021-26328 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-2021-26328?

CVE-2021-26328 primarily affects Amd Epyc 7003 Firmware. In total, 24 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-26328?

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

When was CVE-2021-26328 published?

CVE-2021-26328 was published on 2023-01-11 and last updated on 2026-06-17.

CVE-2021-26328

CVE-2021-26328 is a medium-severity vulnerability in Amd Epyc 7003 Firmware with a CVSS 3.x base score of 4.4. 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-358.

Key facts

Severity: Medium (CVSS 3.x base score 4.4)
EPSS exploit prediction: 0% (8th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-358
Affected product: Amd Epyc 7003 Firmware
Published: 2023-01-11
Last modified: 2026-06-17

Description

Failure to verify the mode of CPU execution at the time of SNP_INIT may lead to a potential loss of memory integrity for SNP guests.

Frequently asked questions

What is CVE-2021-26328?: Failure to verify the mode of CPU execution at the time of SNP_INIT may lead to a potential loss of memory integrity for SNP guests.
How severe is CVE-2021-26328?: CVE-2021-26328 has a CVSS 3.x base score of 4.4, 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 low, and availability low.
Is CVE-2021-26328 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-2021-26328?: CVE-2021-26328 primarily affects Amd Epyc 7003 Firmware. In total, 24 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-26328?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-26328 published?: CVE-2021-26328 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 (24)

cpe:2.3:o:amd:epyc_7003_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_72f3_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_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_75f3_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7643_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_7743_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7763_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7773x_firmware:*:*:*:*:*:*:*:*

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