AMD SEV-SNP Coherency Vulnerability Advisory (CVE-2025-54509)

Vulnerability Overview AMD has released a security advisory (AMD-SB-3039) titled "ASP Incoherent Memory Access." Researchers reported to AMD that a malicious hypervisor can compromise the integrity protection of AMD Secure Encrypted Virtualization – Secure Nested Paging (SEV-SNP) by forcing the AMD Secure Processor (ASP) to operate without maintaining coherence with system memory. According to their paper, hypervisor-controlled system settings allow for the reconfiguration of how the ASP's memory requests interact with the CPU cache. By disabling coherence, the ASP may read stale data from DRAM when copying pages and updating related metadata, causing recent updates from the guest to the CPU cache to be lost. This can undermine SEV-SNP's guest integrity guarantees and allow for data corruption. AMD’s analysis indicates that this issue affects the 4th and 5th Generation EPYC platforms. Successful exploitation requires a malicious or compromised hypervisor capable of modifying the relevant system settings and triggering ASP-managed memory operations. Furthermore, practical exploitation relies on a race condition, requiring precise timing to affect guest integrity. Affected Products AMD EPYC™ Processors - AMD EPYC™ 8004 Series Processors: GenoaPI 1.0.0.H, Release Date: 2025-12-15 - AMD EPYC™ 9004 Series Processors: GenoaPI 1.0.0.H, Release Date: 2025-12-15 - AMD EPYC™ 9005 Series Processors: TurinPI 1.0.0.8, Release Date: 2025-11-26 AMD EPYC™ Embedded Processors - AMD EPYC™ Embedded 8004 Series Processors: EmbGenoaPI-SP5 1.0.0.D, Release Date: 2026-02-02 - AMD EPYC™ Embedded 9004 Series Processors (former codename "Genoa"): EmbGenoaPI-SP5 1.0.0.D, Release Date: 2026-02-02 - AMD EPYC™ Embedded 9004 Series Processors (former codename "Bergamo"): EmbGenoaPI-SP5 1.0.0.D, Release Date: 2026-02-02 - AMD EPYC™ Embedded 9005 Series Processors: EmbeddedTurinPI-SP5 1004, Release Date: 2026-04-13 Remediation AMD recommends updating to the specified Platform Initialization (PI) versions. Mitigations have been released to Original Equipment Manufacturers (OEMs) with the following release dates. Please contact your OEM for BIOS updates specific to your product. Vulnerability Details CVE ID: CVE-2025-54509 CVSS Score: 4.0 (Medium) Description: Improper input handling of the Input/Output Memory Management Unit (IOMMU) in the register interface may allow a privileged attacker to cause incoherent access induced by the AMD Secure Processor (ASP), potentially leading to integrity loss. Acknowledgments AMD thanks Benedict Schlüter and Shweta Shinde of ETH Zurich for reporting this issue and participating in the coordinated vulnerability disclosure. Revision History 2026-06-09: Initial Release Disclaimer The information in this document is for informational purposes only and is subject to change without notice. While precautions have been taken in the preparation of this document, it may contain technical inaccuracies, omissions, and typographical errors. AMD is under no obligation to update or otherwise correct this information. Advanced Micro Devices, Inc. makes no representations or warranties, either expressed or implied, including but not limited to the implied warranties of merchantability or fitness for a particular purpose, regarding the accuracy or completeness of the content of this document. Any use or operation of any AMD hardware, software, or other products described in this document involves security risks that cannot be completely prevented or mitigated. This document does not grant any intellectual property rights. Terms and conditions governing the purchase or use of AMD products apply to any AMD product described in this document and are subject to agreements signed by both parties or AMD’s standard terms and conditions. AMD and the AMD Arrow logo, EPYC, and their combinations are trademarks of Advanced Micro Devices, Inc. CVE and the CVE logo are registered trademarks of The MITRE Corporation. Other product names used in this document are for identification purposes only and may be trademarks of their respective companies. Third-party content may be licensed to you directly by the third party owning that content, rather than by AMD. All linked third-party content is provided "as is" without any express or implied warranties. The use of such third-party content is entirely at your own risk, and AMD assumes no responsibility for any third-party content. You assume all risks arising from the use of third-party content and are fully liable for any damages resulting therefrom. © 2026 Advanced Micro Devices, Inc. All rights reserved.

Goal Reached Thanks to every supporter — we hit 100%!

AMD SEV-SNP Coherency Vulnerability Advisory (CVE-2025-54509)