dbcve.org
Epyc 7003 FirmwareOperating system · Amd

CVE-2021-26331

HIGH · 7.8 CVSS v3.1 Published 2021-11-16
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
80/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
AMD System Management Unit (SMU) contains a potential issue where a malicious user may be able to manipulate mailbox entries leading to arbitrary code execution.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

AMD System Management Unit (SMU) firmware contains a vulnerability where an attacker with local access can manipulate mailbox data structures to achieve arbitrary code execution within the SMU context. The SMU is a dedicated microcontroller managing power, clock, and thermal management on AMD processors.

MitigationApply AMD-provided firmware/BIOS updates that address this vulnerability. Organizations should inventory affected AMD systems and coordinate with hardware vendors for patch deployment.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Epyc 7003 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 7002 FirmwareOperating system
Affected:< romepi-sp3_1.0.0.c
Epyc 7001 FirmwareOperating system
Affected:< naplespi-sp3_1.0.0.g
Epyc 72f3 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 7313 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 7313p FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 7343 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 73f3 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify AMD Epyc processor model
    Run 'dmidecode -t processor' or check /proc/cpuinfo for the CPU model name (e.g., AMD Epyc 7003, 7002, 7001 series)
    Affected if The processor is NOT an AMD Epyc from the 7001, 7002, or 7003 series (or variants like 72f3, 7313, 7313p, 7343, 73f3)
  2. Obtain SMU firmware version
    Use 'ipmitool fru print 0' or 'ipmitool mc info' via the BMC/IPMI interface, or check BIOS/UEFI firmware version information under System Information or Processor Details
    Affected if Unable to retrieve SMU firmware version (system may use different firmware reporting mechanisms)
  3. Compare installed SMU firmware against affected versions
    For AMD Epyc 7003 (including 72f3, 7313, 7313p, 7343, 73f3): check if version is earlier than milanpi-sp3_1.0.0.4. For Epyc 7002: check if version is earlier than romepi-sp3_1.0.0.c. For Epyc 7001: check if version is earlier than naplespi-sp3_1.0.0.g
    Affected if The SMU firmware version is below the specified threshold for your specific Epyc model
  4. Verify local access exposure
    Review system access controls to determine if untrusted local users could interact with BMC, IPMI, or have physical access to manipulate mailbox data structures
    Affected if Untrusted local users have direct access to IPMI/BMC or physical access to the server

You are affected if you run an AMD Epyc 7001, 7002, or 7003 series processor with SMU firmware version below the specified threshold (milanpi-sp3_1.0.0.4, romepi-sp3_1.0.0.c, or naplespi-sp3_1.0.0.g respectively) and untrusted local users can access the system.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply AMD-provided firmware/BIOS updates that address this vulnerability. Organizations should inventory affected AMD systems and coordinate with hardware vendors for patch deployment.

Recommended fix High confidence

milanpi-sp3_1.0.0.4 (Epyc 7003/72f3/7313/7313p/7343/73f3), romepi-sp3_1.0.0.c (Epyc 7002), naplespi-sp3_1.0.0.g (Epyc 7001)

  1. 1. Identify the exact Epyc processor model in the system using BIOS or system information utilities
  2. 2. Download the latest AMD AGESA firmware update from AMD's support website for the specific processor model
  3. 3. Apply the firmware update through the system BIOS update utility, BMC/IPMI firmware update interface, or AMD's firmware update tools
  4. 4. Verify the installed firmware version matches the fixed release: milanpi-sp3_1.0.0.4 (for Epyc 7003/72f3/7313/7313p/7343/73f3), romepi-sp3_1.0.0.c (for Epyc 7002), or naplespi-sp3_1.0.0.g (for Epyc 7001)
  5. 5. Reboot the system to ensure the new firmware is fully applied
Caveat Firmware updates carry inherent risk; ensure backup and test in non-production environment first

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Epyc 7003 Firmware Scoped from the published advisory
  • Consultation8.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,920
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,672.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-26331 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-26331 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data