CVE-2025-61971

SEV-SNP guest integrity loss via unlocked NBIO registers

Published May 13, 2026 · Updated May 13, 2026

Missing lock-bit protection in affected AMD EPYC processors allows local users with host administration to alter SEV-SNP guest execution. NBIO registers remain writable after trusted firmware initializes them, allowing privileged host software to rewrite MMIO routing configuration. Host administrator privileges and an active SEV-SNP guest are required; the documented consequence is guest-integrity loss without confidentiality or availability impact.

CVSS severity5.9
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Missing lock-bit protection in affected AMD EPYC processors allows local users with host administration to alter SEV-SNP guest execution. NBIO registers remain writable after trusted firmware initializes them, allowing privileged host software to rewrite MMIO routing configuration. Host administrator privileges and an active SEV-SNP guest are required; the documented consequence is guest-integrity loss without confidentiality or availability impact.

The record

CVE
CVE-2025-61971
Published
May 13, 2026
Updated
May 13, 2026
Vendor
Advanced Micro Devices, Inc.
Product
AMD EPYC Embedded 8004 Series Processors
Classifications
CWE-1233, CAPEC-680, CAPEC-176, T1565.003
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. May 13, 2026CVE publishedPublication date reported by the CVE source.
  2. May 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Advanced Micro Devices, Inc. · AMD EPYC Embedded 8004 Series ProcessorsAffected versions are unavailable in this record.
Advanced Micro Devices, Inc. · AMD EPYC Embedded 7003 Series ProcessorsAffected versions are unavailable in this record.
Advanced Micro Devices, Inc. · AMD EPYC Embedded 9004 Series ProcessorsAffected versions are unavailable in this record.
Advanced Micro Devices, Inc. · AMD EPYC 9005 Series ProcessorsAffected versions are unavailable in this record.
Advanced Micro Devices, Inc. · AMD EPYC™ 8004 Series ProcessorsAffected versions are unavailable in this record.
Advanced Micro Devices, Inc. · AMD EPYC™ 9004 Series ProcessorsAffected versions are unavailable in this record.
Advanced Micro Devices, Inc. · AMD EPYC Embedded 9005 Series ProcessorsAffected versions are unavailable in this record.
Advanced Micro Devices, Inc. · AMD EPYC™ 7003 Series ProcessorsAffected versions are unavailable in this record.

Published CVSS scores

5.9Advanced Micro DevicesCVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:H/SA:N

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)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1233Security-Sensitive Hardware Controls with Missing Lock Bit Protection
CAPEC-680Exploitation of Improperly Controlled Registers
CAPEC-176Configuration/Environment Manipulation
T1565.003Runtime Data Manipulation

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo