What is CVE-2021-26400?

CVE-2021-26400 is a medium-severity vulnerability in AMD Processors. CVSS score: 4.0/10. Published 2022-05-11.

How severe is CVE-2021-26400?

Medium severity. CVSS v3 base score is 4.0 out of 10.

Vulnerability in AMD Processors

CVE-2021-26400

AMD processors may speculatively re-order load instructions which can result in stale data being observed when multiple processors are operating on shared memory, resulting in potential data leakage.

Published 2022-05-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.0 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.002 (12.8th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 12.8% 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

AMD Processors — versions Processor All Supported Processors
AMD CPU

References

www.amd.com/en/corporate/product-security/bulletin/amd-sb-1035 (Vendor Advisory)

Frequently asked questions

What is CVE-2021-26400?: CVE-2021-26400 is a medium-severity vulnerability in AMD Processors. CVSS score: 4.0/10. Published 2022-05-11.
How severe is CVE-2021-26400?: Medium severity. CVSS v3 base score is 4.0 out of 10.