Cyber Resilience

CVE-2021-26336

Medium

Published: 16 November 2021

Published
16 November 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0013 31.4th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-26336 is a medium-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Amd Epyc 7003 Firmware. Its CVSS base score is 5.5 (Medium).

Operationally, ranked at the 31.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

amd
epyc 7003 firmware
≤ milanpi-sp3_1.0.0.4
amd
epyc 7002 firmware
≤ romepi-sp3_1.0.0.c
amd
epyc 72f3 firmware
≤ milanpi-sp3_1.0.0.4
amd
epyc 7313 firmware
≤ milanpi-sp3_1.0.0.4
amd
epyc 7313p firmware
≤ milanpi-sp3_1.0.0.4
amd
epyc 7343 firmware
≤ milanpi-sp3_1.0.0.4
amd
epyc 73f3 firmware
≤ milanpi-sp3_1.0.0.4
amd
epyc 7413 firmware
≤ milanpi-sp3_1.0.0.4
amd
epyc 7443 firmware
≤ milanpi-sp3_1.0.0.4
amd
epyc 7443p firmware
≤ milanpi-sp3_1.0.0.4
+85 more product configuration(s) — see NVD for full list

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-119

Ongoing control assessments and code testing (static/dynamic analysis, fuzzing) surface memory buffer restriction failures, which are then remediated before release.

addresses: CWE-119

Managed runtimes used by platform-independent applications (e.g., JVM, CLR) enforce memory safety, preventing most buffer overflows that require direct memory manipulation.

addresses: CWE-119

Memory protections (e.g., W^X, ASLR) make exploitation of buffer-boundary violations far harder to turn into code execution.

addresses: CWE-119

Detects exploitation attempts that produce memory corruption, crashes, or anomalous behavior.

References