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AMD Security Bulletin AMD-SB-3016, April 2026

Supermicro is aware of the security issue where an internal security audit found a potential vulnerability that could allow a malicious hypervisor to direct the IOMMU to write into Secure Encrypted Virtualization-Secure Nested Paging (SEV-SNP) guest memory. AMD released mitigations for this vulnerability. This vulnerability affects BIOS in Supermicro H12, H13, and H14 products.

CVE:

  • CVE-2023-20585
  • Severity: Medium

Findings:

Insufficient checks of the RMP on host buffer access in IOMMU may allow an attacker with privileges and a compromised hypervisor to trigger an out of bounds condition without RMP checks, resulting in a potential loss of confidential guest integrity.

Affected products:

Supermicro BIOS on the server H12, H13, and H14 motherboards.

AMD Motherboard GenerationBIOS Version with Fix
H12 – H12SSW-AN6 – EPYC™ 7002/7003 seriesv 3.4
H12 – H12SSW-iNR/NTR – EPYC™ 7002/7003 seriesv 3.5
H12 – H12SSW-iNL/NTL – EPYC™ 7002/7003 seriesv 3.5
H12 – H12DSG-O-CPU – EPYC™ 7002/7003 seriesv 3.5
H12 – H12DST-B – EPYC™ 7002/7003 seriesv 3.5
H12 – H12SST-PS – EPYC™ 7002/7003 seriesv 3.5
H12 – H12SSW-iN/NT – EPYC™ 7002/7003 seriesv 3.5
H12 – BH12SSi-M25 – EPYC™ 7002/7003 seriesv 3.5
H12 – H12DSU-iN – EPYC™ 7002/7003 seriesv 3.5
H12 – H12SSFF-AN6 – EPYC™ 7002/7003 seriesv 3.5
H12 – H12SSL-i/C/CT/NT – EPYC™ 7002/7003 seriesv 3.5
H12 – H12DSi-N6/NT6 – EPYC™ 7002/7003 seriesv 3.5
H12 – H12SSFR-AN6 – EPYC™ 7002/7003 seriesv 3.5
H12 – H12DSG-Q-CPU6 – EPYC™ 7002/7003 seriesv 3.5
H12 – H12SSG-AN6 – EPYC™ 7002/7003 seriesv 3.5
H12 – H12DGQ-NT6 – EPYC™ 7002/7003 seriesv 3.5
H12 – H12SSG-ANP6 – EPYC™ 7002/7003 seriesv 3.5
H12 – H12DGO-6 – EPYC™ 7002/7003 seriesv 3.5
H12 – H12DSU-iNR – EPYC™ 7002/7003 seriesv 3.5
H13 – H13SVW-N/NT – EPYC™ 8004 seriesv 1.5
H13 – H13SSW – EPYC™ 9004/9005 seriesv 3.7
H13 – H13DSH – EPYC™ 9004/9005 seriesv 3.7a
H13 – H13DSG-O-CPU – EPYC™ 9004/9005 seriesv 3.8
H13 – H13SST-G/GC – EPYC™ 9004/9005 seriesv 3.5
H13 – H13SSL-N/NT – EPYC™ 9004/9005 seriesv 3.7
H13 – H13SSH – EPYC™ 9004/9005 seriesv 3.7b
H13 – H13DSG-O-CPU-D – EPYC™ 9004 seriesv 3.7a
H13 – H13SSF – EPYC™ 9004/9005 seriesv 3.7a
H13 – H13DSG-OM – EPYC™ 9004/9005 seriesv 3.7a
H14 – H14DSH – EPYC™ 9004/9005 seriesv 1.7a
H14 – H14SST-G – EPYC™ 9004/9005 seriesv 1.7a
H14 – H14DSG-OD – EPYC™ 9004/9005 seriesv 1.7a
H14 – H14SHM – EPYC™ 9004/9005 seriesv 1.7
H14 – H14DSG-O-CPU – EPYC™ 9004/9005 seriesv 1.7a
H14 – H14SSL-N/NT – EPYC™ 9004/9005 seriesv 1.7
H14 – H14DSG-OM – EPYC™ 9004/9005 seriesv 1.1b

Remediation:

  • All affected Supermicro motherboard SKUs will require a BIOS update to mitigate this potential vulnerability.
  • Updated BIOS firmware has been created to mitigate this potential vulnerability. Supermicro is currently testing and validating affected products. Please check Release Notes for the resolution.