EDK II Mitigations for Transient Scheduler Attacks (TSA)
Summary
A researcher reported that the existing mitigations for Transient Scheduler Attacks (TSA) on AMD processors could be insufficient in certain scenarios involving System Management Mode (SMM) in EDK II. According to the report, a privileged kernel-mode attacker can trigger a System Management Interrupt (SMI) and subsequently use TSA-style transient execution measured via performance monitoring counters to infer values left in microarchitectural structures by SMM.
AMD has assessed the reported issue and determined that it results from the absence of TSA (Transient Scheduler Attacks) mitigations in EDK2. AMD recommends that customers implement the previously disclosed TSA mitigations covered in AMD-SB-7029: AMD Transient Scheduler Attacks and apply forthcoming EDK II or Platform Initialization (PI) firmware updates to address and mitigate this vulnerability.
Customers who are members of the EDK II InfoSec community can find the corresponding submission at the link below:
CVE Details
Refer to Glossary for explanation of terms
CVE |
CVE Description |
CVSS Base Score |
CVE-2026-18448 (non-AMD) |
Insufficient Transient Scheduler Attack (TSA) mitigations in EDK II could allow a ring-0 attacker to infer residual microarchitectural state left by SMM execution, potentially resulting in disclosure of SMRAM contents. |
5.6 CWE-1420: Exposure of Sensitive Information during Transient Execution |
Specific CVSS scores may change subject to your implementation. We encourage you to calculate CVSS scores independently for your system.
Affected Products and Mitigation
AMD recommends implementing the mitigations included in the previously published security bulletin AMD-SB-7029 (AMD-SB-7029: AMD Transient Scheduler Attacks) and the EDK II patch when available.
For AMD Ryzen™ series processors, AMD plans to release updated Platform Initialization (PI) firmware packages which include the EDK II patch. (note the PI firmware versions will be released by AMD to the Original Equipment Manufacturers (OEM) on the dates listed below). Please contact your OEM for the BIOS update specific to your product(s).
*Note: Products believed to not be affected by the listed CVEs are not included.
AMD EPYC™ Series Processors
Product |
CVE ID |
Mitigation |
Mitigation Release Date |
AMD EPYC™ 4004 Series Processors |
CVE-2026-18448 (non-AMD) |
ComboAM5PI 1.2.0.3m or EDKII Patch |
2026-09-24 (PI release) |
AMD EPYC™ 4005 Series Processors |
CVE-2026-18448 (non-AMD) |
ComboAM5PI 1.2.0.3m or EDKII Patch |
2026-09-24 (PI release) |
AMD EPYC™ 7003 Series Processors |
CVE-2026-18448 (non-AMD) |
EDKII Patch |
Target release planned for Nov'26 |
AMD EPYC™ 8004 Series Processors |
CVE-2026-18448 (non-AMD) |
EDKII Patch |
Target release planned for Nov'26 |
AMD EPYC™ 8005 Series Processors |
CVE-2026-18448 (non-AMD) |
EDKII Patch |
Target release planned for Nov'26 |
AMD EPYC™ 9004 Series Processors |
CVE-2026-18448 (non-AMD) |
EDKII Patch |
Target release planned for Nov'26 |
AMD EPYC™ 9005 Series Processors |
CVE-2026-18448 (non-AMD) |
EDKII Patch |
Target release planned for Nov'26 |
AMD EPYC™ Embedded Series Processors
Product |
CVE ID |
Mitigation |
Mitigation Release Date |
AMD EPYC™ Embedded 2005 Series Processors |
CVE-2026-18448 (non-AMD) |
EDKII patch |
Target release planned for Nov'26 |
AMD EPYC™ Embedded 7003 Series Processors |
CVE-2026-18448 (non-AMD) |
EDKII patch |
Target release planned for Nov'26 |
AMD EPYC™ Embedded 8004 Series Processors |
CVE-2026-18448 (non-AMD) |
EDKII patch |
Target release planned for Nov'26 |
AMD EPYC™ Embedded 9004 Series Processors |
CVE-2026-18448 (non-AMD) |
EDKII patch |
Target release planned for Nov'26 |
AMD EPYC™ Embedded 9004 Series Processors |
CVE-2026-18448 (non-AMD) |
EDKII patch |
Target release planned for Nov'26 |
AMD EPYC™ Embedded 9005 Series Processors |
CVE-2026-18448 (non-AMD) |
EDKII patch |
Target release planned for Nov'26 |
AMD Ryzen™ Series Processors
Product |
CVE ID |
Mitigation |
Mitigation Release Date |
AMD Ryzen™ 5000 Series Desktop Processors |
CVE-2026-18448 (non-AMD) |
ComboAM4v2PI_1.2.0.13 or EDKII Patch |
Target release planned for Nov'26 |
AMD Ryzen™ 5000 Series Desktop Processors with Radeon™ Graphics |
CVE-2026-18448 (non-AMD) |
ComboAM4v2PI_1.2.0.13 or EDKII Patch |
Target release planned for Nov'26 |
AMD Ryzen™ 5000 Series Mobile Processors with Radeon™ Graphics |
CVE-2026-18448 (non-AMD) |
CezannePI-FP6_1.0.1.1f or EDKII Patch |
2026-10-27 |
AMD Ryzen™ 6000 Series Processors with Radeon™ Graphics |
CVE-2026-18448 (non-AMD) |
RembrandtPI-FP7_1.0.0.Bj or EDKII Patch |
2026-10-13 |
AMD Ryzen™ 7000 Series Desktop Processors |
CVE-2026-18448 (non-AMD) |
ComboAM5PI 1.1.0.3j or EDKII Patch |
2026-10-14 |
ComboAM5PI 1.0.0.h or EDKII Patch |
2026-10-08 |
||
ComboAM5PI 1.2.0.3m or EDKII Patch |
2026-09-24 |
||
ComboAM5PI_1.3.0.1e or EDKII Patch |
2026-09-24 |
||
AMD Ryzen™ 7030 Series Mobile Processors with Radeon™ Graphics |
CVE-2026-18448 (non-AMD) |
CezannePI-FP6_1.0.1.1f or EDKII Patch |
2026-10-27 |
AMD Ryzen™ 7035 Series Processors with Radeon™ Graphics |
CVE-2026-18448 (non-AMD) |
RembrandtPI-FP7_1.0.0.Bj |
2026-10-13 |
AMD Ryzen™ 7040 Series Mobile Processors with Radeon™ Graphics |
CVE-2026-18448 (non-AMD) |
PhoenixPI-FP8-FP7_1.2.0.0k or EDKII Patch |
2026-09-22 |
AMD Ryzen™ 7045 Series Mobile Processors with Radeon™ Graphics |
CVE-2026-18448 (non-AMD) |
DragonRangeFL1 PI-1.0.0.3p or EDKII Patch |
2026-09-16 |
AMD Ryzen™ 8000 Series Desktop Processors |
CVE-2026-18448 (non-AMD) |
ComboAM5PI 1.2.0.3m or EDKII Patch |
2026-10-14 |
ComboAM5PI 1.1.0.3j or EDKII Patch |
2026-09-24 |
||
AMD Ryzen™ 8040 Series Mobile Processors with Radeon™ Graphics |
CVE-2026-18448 (non-AMD) |
PhoenixPI-FP8-FP7_1.2.0.0k or EDKII Patch |
2026-09-22 |
AMD Ryzen™ 9000 Series Desktop Processors |
CVE-2026-18448 (non-AMD) |
ComboAM5PI 1.2.0.3m or EDKII Patch |
2026-09-24 |
ComboAM5PI_1.3.0.1e or EDKII Patch |
2026-09-24 |
||
AMD Ryzen™ 9000HX Series Processors |
CVE-2026-18448 (non-AMD) |
FireRangeFL1 PI-1.0.0.0j or EDKII Patch |
2026-09-22 |
AMD Ryzen™ AI 300 Series Processors |
CVE-2026-18448 (non-AMD) |
StrixKrackanPI-FP8_1.1.0.2h or EDKII Patch |
2026-09-30 |
StrixKrackanPI-FP8_1.1.0.0i or EDKII Patch |
2026-09-22 |
||
AMD Ryzen™ AI 400 Series Desktop Processors |
CVE-2026-18448 (non-AMD) |
ComboAM5PI_1.3.0.1e or EDKII Patch |
2026-09-24 |
AMD Ryzen™ AI 400 Series Processors |
CVE-2026-18448 (non-AMD) |
GorgonPI-FP8_1.0.0.2g or EDKII Patch |
2026-09-16 |
AMD Ryzen™ AI Max 300 Series Processors |
CVE-2026-18448 (non-AMD) |
StrixHalo PI-FP11_1.0.0.2e or EDKII Patch |
2026-10-27 |
AMD Ryzen™ AI Max 400 Series Processors |
CVE-2026-18448 (non-AMD) |
GorgonHalo PI FP11_1.0.0.0d or EDKII Patch |
2026-10-29 |
AMD Ryzen™ PRO 9000 Series Processors |
CVE-2026-18448 (non-AMD) |
ComboAM5PI 1.2.0.3m or EDKII Patch |
2026-09-24 |
AMD Ryzen™ Threadripper™ PRO 7000 WX-Series Processors |
CVE-2026-18448 (non-AMD) |
StormPeakPI-SP6-1.1.0.0n or EDKII Patch |
Target release planned for Nov'26 |
StormPeakPI-SP6-1.0.0.1p or EDKII Patch |
Target release planned for Nov'26 |
||
ShimadaPeakPI-SP6-1.0.0.1i or EDKII Patch |
2026-10-28 |
||
AMD Ryzen™ Z1 Series Processors |
CVE-2026-18448 (non-AMD) |
PhoenixPI-FP8-FP7_1.2.0.0k or EDKII Patch |
2026-09-22 |
AMD Ryzen™ Z2 Series Processors Extreme |
CVE-2026-18448 (non-AMD) |
GorgonPI-FP8_1.0.0.2g or EDKII Patch |
2026-09-16 |
AMD Ryzen™ Embedded Series Processors
Product |
CVE ID |
Mitigation |
Mitigation Release Date |
AMD Ryzen™ Embedded 5000 Series Processors |
CVE-2026-18448 (non-AMD) |
Version TBD |
Target release planned for Nov'26 |
AMD Ryzen™ Embedded 7000 Series Processors |
CVE-2026-18448 (non-AMD) |
Version TBD |
Target release planned for Nov'26 |
AMD Ryzen™ Embedded 8000 Series Processors |
CVE-2026-18448 (non-AMD) |
Version TBD |
Target release planned for Nov'26 |
AMD Ryzen™ Embedded 9000 Series Processors |
CVE-2026-18448 (non-AMD) |
Version TBD |
Target release planned for Nov'26 |
AMD Ryzen™ Embedded P100 Series Processors |
CVE-2026-18448 (non-AMD) |
Version TBD |
Target release planned for Nov'26 |
AMD Ryzen™ Embedded R1000 Series Processors |
CVE-2026-18448 (non-AMD) |
Version TBD |
Target release planned for Nov'26 |
AMD Ryzen™ Embedded R2000 Series Processors |
CVE-2026-18448 (non-AMD) |
Version TBD |
Target release planned for Nov'26 |
AMD Ryzen™ Embedded V1000 Series Processors |
CVE-2026-18448 (non-AMD) |
Version TBD |
Target release planned for Nov'26 |
AMD Ryzen™ Embedded V1000 Series Processors |
CVE-2026-18448 (non-AMD) |
Version TBD |
Target release planned for Nov'26 |
AMD Ryzen™ Embedded V2000 Series Processors |
CVE-2026-18448 (non-AMD) |
Version TBD |
Target release planned for Nov'26 |
AMD Ryzen™ Embedded V3000 Series Processors |
CVE-2026-18448 (non-AMD) |
Version TBD |
Target release planned for Nov'26 |
References
Acknowledgement
AMD thanks the following for reporting and engaging in coordinated vulnerability disclosure:
- External Researchers Benedict Schlüter, Alessandro Vezzu, Shweta Shinde of ETH Zurich and Daniel Moghimi of Google Research
Revisions
| Revision Date | Description |
| 2026-11-10 | Initial version |
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