TDXRay: Microarchitectural Side-Channel Analysis of Intel TDX for Real-World Workloads

Summary

AMD was made aware of a researcher's report titled “TDXRay: Microarchitectural Side-Channel Analysis of Intel TDX for Real-World Workloads.”

The researchers’ paper introduces TDXRay, a host-side framework that combines four primitives—SEPTrace, Load+Probe, TSX-Probe, and MWAIT-Probe—to trace memory access patterns of Intel TDX Confidential VMs at both page-level and cache-line granularity. The paper was shared for review to assess any potential impact on AMD products.

AMD believes that all side-channel techniques demonstrated in the paper fall within the category of already known, documented, and out-of-scope behaviors as defined in the published Secure Encrypted Virtualization – Secure Nested Paging

(SEV-SNP) threat model. The paper does not introduce any new vulnerabilities in AMD products.

AMD recommends software developers employ existing best practices, including constant-time algorithms, and avoiding secret-dependent data accesses where appropriate. 

Acknowledgement 

AMD thanks Hosein Yavarzadeh, Tristan Hornetz, and the other authors for submitting the report.

DISCLAIMER

The information contained herein is for informational purposes only and is subject to change without notice. While every precaution has been taken in the preparation of this document, it may contain technical inaccuracies, omissions and typographical errors, and AMD is under no obligation to update or otherwise correct this information. Advanced Micro Devices, Inc. makes no representations or warranties with respect to the accuracy or completeness of the contents of this document, and assumes no liability of any kind, including the implied warranties of noninfringement, merchantability or fitness for particular purposes, with respect to the operation or use of AMD hardware, software or other products described herein. Any computer system has risks of security vulnerabilities that cannot be completely prevented or mitigated. No license, including implied or arising by estoppel, to any intellectual property rights is granted by this document. Terms and limitations applicable to the purchase or use of AMD’s products are as set forth in a signed agreement between the parties or in AMD's Standard Terms and Conditions of Sale.

AMD, the AMD Arrow logo, EPYC, and combinations thereof 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 publication 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 that owns the content and is not licensed to you by AMD. ALL LINKED THIRD-PARTY CONTENT IS PROVIDED ‘AS IS’ WITHOUT A WARRANTY OF ANY KIND. USE OF SUCH THIRD-PARTY CONTENT IS DONE AT YOUR SOLE DISCRETION AND UNDER NO CIRCUMSTANCES WILL AMD BE LIABLE TO YOU FOR ANY THIRD PARTY CONTENT. YOU ASSUME ALL RISK AND ARE SOLELY RESPONSIBILITY FOR ANY DAMAGES THAT MAY ARISE FROM YOUR USE OF THIRD-PARTY CONTENT.

© 2026 Advanced Micro Devices, Inc. All rights reserved.