CVE-2021-26336

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: 2021-11-16 · updated 2026-06-17
Weakness: CWE-119

Description

Insufficient bounds checking in System Management Unit (SMU) may cause invalid memory accesses/updates that could result in SMU hang and subsequent failure to service any further requests from other components.

Affected products

AMD Epyc 7002 Firmware: before romepi-sp3_1.0.0.c — fixed in romepi-sp3_1.0.0.c
AMD Epyc 7003 Firmware: before milanpi-sp3_1.0.0.4 — fixed in milanpi-sp3_1.0.0.4
AMD Epyc 7232P Firmware: before romepi-sp3_1.0.0.c — fixed in romepi-sp3_1.0.0.c
AMD Epyc 7252 Firmware: before romepi-sp3_1.0.0.c — fixed in romepi-sp3_1.0.0.c
AMD Epyc 7262 Firmware: before romepi-sp3_1.0.0.c — fixed in romepi-sp3_1.0.0.c
AMD Epyc 7272 Firmware: before romepi-sp3_1.0.0.c — fixed in romepi-sp3_1.0.0.c
AMD Epyc 7282 Firmware: before romepi-sp3_1.0.0.c — fixed in romepi-sp3_1.0.0.c
AMD Epyc 72F3 Firmware: before milanpi-sp3_1.0.0.4 — fixed in milanpi-sp3_1.0.0.4
AMD Epyc 7302 Firmware: before romepi-sp3_1.0.0.c — fixed in romepi-sp3_1.0.0.c
AMD Epyc 7302P Firmware: before romepi-sp3_1.0.0.c — fixed in romepi-sp3_1.0.0.c
AMD Epyc 7313 Firmware: before milanpi-sp3_1.0.0.4 — fixed in milanpi-sp3_1.0.0.4
AMD Epyc 7313P Firmware: before milanpi-sp3_1.0.0.4 — fixed in milanpi-sp3_1.0.0.4
AMD Epyc 7343 Firmware: before milanpi-sp3_1.0.0.4 — fixed in milanpi-sp3_1.0.0.4
AMD Epyc 7352 Firmware: before romepi-sp3_1.0.0.c — fixed in romepi-sp3_1.0.0.c
AMD Epyc 73F3 Firmware: before milanpi-sp3_1.0.0.4 — fixed in milanpi-sp3_1.0.0.4
AMD Epyc 7402 Firmware: before romepi-sp3_1.0.0.c — fixed in romepi-sp3_1.0.0.c
AMD Epyc 7402P Firmware: before romepi-sp3_1.0.0.c — fixed in romepi-sp3_1.0.0.c
AMD Epyc 7413 Firmware: before milanpi-sp3_1.0.0.4 — fixed in milanpi-sp3_1.0.0.4
AMD Epyc 7443 Firmware: before milanpi-sp3_1.0.0.4 — fixed in milanpi-sp3_1.0.0.4
AMD Epyc 7443P Firmware: before milanpi-sp3_1.0.0.4 — fixed in milanpi-sp3_1.0.0.4
AMD Epyc 7452 Firmware: before romepi-sp3_1.0.0.c — fixed in romepi-sp3_1.0.0.c
AMD Epyc 7453 Firmware: before milanpi-sp3_1.0.0.4 — fixed in milanpi-sp3_1.0.0.4
AMD Epyc 74F3 Firmware: before milanpi-sp3_1.0.0.4 — fixed in milanpi-sp3_1.0.0.4
AMD Epyc 7502 Firmware: before romepi-sp3_1.0.0.c — fixed in romepi-sp3_1.0.0.c
AMD Epyc 7502P Firmware: before romepi-sp3_1.0.0.c — fixed in romepi-sp3_1.0.0.c
AMD Epyc 7513 Firmware: before milanpi-sp3_1.0.0.4 — fixed in milanpi-sp3_1.0.0.4
AMD Epyc 7532 Firmware: before romepi-sp3_1.0.0.c — fixed in romepi-sp3_1.0.0.c
AMD Epyc 7542 Firmware: before romepi-sp3_1.0.0.c — fixed in romepi-sp3_1.0.0.c
AMD Epyc 7543 Firmware: before milanpi-sp3_1.0.0.4 — fixed in milanpi-sp3_1.0.0.4
AMD Epyc 7543P Firmware: before milanpi-sp3_1.0.0.4 — fixed in milanpi-sp3_1.0.0.4

How to fix

Upgrade to a fixed version: AMD Epyc 7002 Firmware romepi-sp3_1.0.0.c; AMD Epyc 7003 Firmware milanpi-sp3_1.0.0.4; AMD Epyc 7232P Firmware romepi-sp3_1.0.0.c; AMD Epyc 7252 Firmware romepi-sp3_1.0.0.c; AMD Epyc 7262 Firmware romepi-sp3_1.0.0.c; AMD Epyc 7272 Firmware romepi-sp3_1.0.0.c; AMD Epyc 7282 Firmware romepi-sp3_1.0.0.c; AMD Epyc 72F3 Firmware milanpi-sp3_1.0.0.4; AMD Epyc 7302 Firmware romepi-sp3_1.0.0.c; AMD Epyc 7302P Firmware romepi-sp3_1.0.0.c; AMD Epyc 7313 Firmware milanpi-sp3_1.0.0.4; AMD Epyc 7313P Firmware milanpi-sp3_1.0.0.4. Check the vendor advisory for mitigations.

References

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