This vulnerability (CVE-2025-61971) in AMD EPYC 9004 Series Processors arises from missing protection on security-sensitive hardware controls, specifically lacking lock bit protection. This weakness enables a malicious hypervisor to execute arbitrary code on the AMD Secure Processor, leading to escalated MMIO read and write permissions. The consequence is a compromise of confidentiality and integrity for SEV-SNP guests. Google has implemented mitigations for Confidential VM instances leveraging AMD SEV-SNP technology. The vulnerability is tracked under CWE-1233 and has a CVSS 4.0 score of 5.9, indicating medium severity.

The vulnerability allows a malicious hypervisor to execute arbitrary code on the AMD Secure Processor, which escalates MMIO read and write permissions. This compromises the confidentiality and integrity of SEV-SNP guests, potentially exposing sensitive data or allowing unauthorized modifications within virtualized environments relying on AMD SEV-SNP.

Google has already applied mitigations to Confidential VM instances using AMD SEV-SNP technology. According to the vendor advisory, no customer action is needed at this time. Users should monitor official AMD advisories for any future updates or patches.