Hardware: AMD NBIO Lock Bit Bypass for MMIO Routing
CVE-2025-61971 Published on May 13, 2026
Missing lock bit protection for NBIO registers could allow a local admin-privileged attacker to modify MMIO routing configurations, potentially resulting in loss of SEV-SNP guest integrity.
Weakness Type
Improper Hardware Lock Protection for Security Sensitive Controls
The product implements a register lock bit protection feature that permits security sensitive controls to modify the protected configuration.
Affected Versions
AMD EPYC™ 9004 Series Processors:- Version GenoaPI_1.0.0.H is unaffected.
- Version MilanPI-SP3_1.0.0.J is unaffected.
- Version TurinPI_1.0.0.8 is unaffected.
- Version GenoaPI_1.0.0.H is unaffected.
- Version EmbMilanPI-SP3 1.0.0.D is unaffected.
- Version EmbGenoaPI-SP5 1.0.0.D is unaffected.
- Version EmbGenoaPI-SP5 1.0.0.D is unaffected.
- Version EmbGenoaPI-SP5 1.0.0.D is unaffected.
- Version EmbeddedTurinPI_SP5_1004 is unaffected.
Exploit Probability
EPSS
0.01%
Percentile
1.78%
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.