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Epyc 7232p FirmwareOperating system · Amd

CVE-2021-26326

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
Failure to validate VM_HSAVE_PA during SNP_INIT may result in a loss of memory integrity.

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 SEV-SNP (Secure Encrypted Virtualization with Secure Nested Paging) fails to validate the VM_HSAVE_PA hypervisor parameter during SNP initialization. Without proper validation, a malicious or compromised hypervisor could supply an invalid memory address, potentially leading to loss of memory integrity for protected virtual machines.

MitigationApply AMD-provided firmware updates for the Platform Security Processor (PSP) that add proper validation of the VM_HSAVE_PA parameter during SNP initialization, and ensure hypervisors are updated to support the validated initialization sequence.

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 7232p FirmwareOperating system
Affected:< romepi-sp3_1.0.0.c
Epyc 7763 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 7713p FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 7713 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 7663 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 7643 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 75f3 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 7543p 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 the AMD Epyc processor model
    Run 'cat /proc/cpuinfo | grep -E "model name|flags" | head -5' or use 'lscpu' to confirm the processor is an AMD Epyc from the 7002 (Rome) or 7003 (Milan) series.
    Affected if The processor is not an AMD Epyc 7002/7003 series processor, as this vulnerability only affects those specific families.
  2. Check the PSP firmware version
    Inspect the Platform Security Processor (PSP) firmware version via 'cat /sys/firmware/amd/psp_version' or check BIOS/UEFI firmware logs. For AMD Epyc Rome, look for version string starting with 'romepi-sp3'. For Milan, look for 'milanpi-sp3'.
    Affected if The PSP firmware version is earlier than 'romepi-sp3_1.0.0.c' for Rome processors or earlier than 'milanpi-sp3_1.0.0.4' for Milan processors.
  3. Verify if SEV-SNP is enabled
    Check if SEV-SNP is active by examining 'cat /sys/kernel/debug/sev' or 'kvm-psw' output. Also check for 'sev-snp' in /proc/cmdline or dmesg logs related to KVM and SEV.
    Affected if SEV-SNP is enabled and the PSP firmware version is below the fixed versions listed in step 2.
  4. Check VM_HSAVE_PA configuration
    If using a hypervisor, inspect the hypervisor configuration or logs for the VM_HSAVE_PA parameter being passed during VM initialization. This parameter specifies the hypervisor save area address.
    Affected if A hypervisor is providing a VM_HSAVE_PA value and SEV-SNP is enabled with vulnerable firmware, creating the conditions for exploitation.

You are affected if you are running an AMD Epyc 7002/7003 processor with PSP firmware earlier than the fixed versions AND have SEV-SNP enabled in your environment.

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 updates for the Platform Security Processor (PSP) that add proper validation of the VM_HSAVE_PA parameter during SNP initialization, and ensure hypervisors are updated to support the validated initialization sequence.

Recommended fix High confidence

romepi-sp3_1.0.0.c for Epyc 7232p; milanpi-sp3_1.0.0.4 for Epyc 7763/7713p/7713/7663/7643/75f3/7543p

  1. Identify the exact Epyc processor model in your system using BIOS or system information tools
  2. Contact your server hardware vendor (e.g., Dell, HP, Lenovo, Supermicro) to obtain the specific firmware update containing the security fix
  3. Obtain the appropriate firmware version: romepi-sp3_1.0.0.c or later for Epyc 7232p; milanpi-sp3_1.0.0.4 or later for Epyc 7763, 7713p, 7713, 7663, 7643, 75f3, 7543p
  4. Review vendor documentation for firmware update procedures and ensure understanding of prerequisites
  5. Back up any critical data and create a system state backup if possible
  6. Apply the firmware update following the vendor's recommended process, which typically involves running a firmware update utility or using out-of-band management (iLo, iDRAC, XCC)
  7. Verify the firmware version has been successfully applied post-update
Caveat Firmware updates may require system downtime and should be performed in accordance with vendor guidelines to avoid boot issues

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

Fix this in Epyc 7232p Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,680
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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-2021-26326 in production — separate from our analysis above.

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