What is CVE-2021-26328?

CVE-2021-26328 is a medium-severity vulnerability in AMD 3rd Gen Epyc, classified under CWE-358. CVSS score: 4.4/10. Published 2023-01-11.

How severe is CVE-2021-26328?

Medium severity. CVSS v3 base score is 4.4 out of 10.

Vulnerability in AMD 3rd Gen Epyc

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.

Published 2023-01-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L.

EPSS exploit prediction

EPSS: 0.002 (7.3th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 7.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-358

References

www.amd.com/en/corporate/product-security/bulletin/AMD-SB-1032 (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2021-26328?: CVE-2021-26328 is a medium-severity vulnerability in AMD 3rd Gen Epyc, classified under CWE-358. CVSS score: 4.4/10. Published 2023-01-11.
How severe is CVE-2021-26328?: Medium severity. CVSS v3 base score is 4.4 out of 10.