CVE-2021-26325

Service interruption via malformed guest request

Published Nov 16, 2021 · Updated Sep 16, 2024

Improper input validation in AMD 3rd Gen EPYC firmware before MilanPI-SP3_1.0.0.4 allows attackers to interrupt service. The SNP_GUEST_REQUEST handler processes insufficiently validated command input, which can trigger a firmware data abort. AMD has not disclosed the malformed field, the privileges required to reach the command, or whether recovery requires a guest or host restart.

CVSS severityUnavailable
Unscored
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in AMD 3rd Gen EPYC firmware before MilanPI-SP3_1.0.0.4 allows attackers to interrupt service. The SNP_GUEST_REQUEST handler processes insufficiently validated command input, which can trigger a firmware data abort. AMD has not disclosed the malformed field, the privileges required to reach the command, or whether recovery requires a guest or host restart.

The record

CVE
CVE-2021-26325
Published
Nov 16, 2021
Updated
Sep 16, 2024
Vendor
Advanced Micro Devices, Inc.
Product
3rd Gen AMD EPYC Processors
Classifications
CWE-20, T1499
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Nov 16, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <MilanPI-SP3_1.0.0.4

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

Advanced Micro Devices, Inc. · 3rd Gen AMD EPYC Processorsversion=unspecified <MilanPI-SP3_1.0.0.4

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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