CVE-2021-26404

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-01-11 · updated 2026-06-17
Weakness: CWE-20

Description

Improper input validation and bounds checking in SEV firmware may leak scratch buffer bytes leading to potential information disclosure.

Affected products

AMD Epyc 7003 Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7313 Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7313P Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7343 Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7373X Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 73F3 Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7413 Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7443 Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7443P Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7453 Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7473X Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 74F3 Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7513 Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7543 Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7543P Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7573X Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 75F3 Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7643 Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7663 Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7713 Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7713P Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7763 Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9
AMD Epyc 7773X Firmware: before milanpi-sp3_1.0.0.9 — fixed in milanpi-sp3_1.0.0.9

How to fix

Upgrade to a fixed version: AMD Epyc 7003 Firmware milanpi-sp3_1.0.0.9; AMD Epyc 7313 Firmware milanpi-sp3_1.0.0.9; AMD Epyc 7313P Firmware milanpi-sp3_1.0.0.9; AMD Epyc 7343 Firmware milanpi-sp3_1.0.0.9; AMD Epyc 7373X Firmware milanpi-sp3_1.0.0.9; AMD Epyc 73F3 Firmware milanpi-sp3_1.0.0.9; AMD Epyc 7413 Firmware milanpi-sp3_1.0.0.9; AMD Epyc 7443 Firmware milanpi-sp3_1.0.0.9; AMD Epyc 7443P Firmware milanpi-sp3_1.0.0.9; AMD Epyc 7453 Firmware milanpi-sp3_1.0.0.9; AMD Epyc 7473X Firmware milanpi-sp3_1.0.0.9; AMD Epyc 74F3 Firmware milanpi-sp3_1.0.0.9. Check the vendor advisory for mitigations.

References

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