AMD EPYC SEV firmware: Improper access control in mirrored memory regions
Summary
AMD Secure Encrypted Virtualization (SEV) firmware on several EPYC server and EPYC Embedded processor families contains an improper access control flaw in mirrored or aliased memory regions. A malicious hypervisor with high privileges could change the encryption bit of guest context pages, which may lead to a loss of integrity for guest data. The attack is local and requires control of the hypervisor or host, so the risk is mainly relevant for multi-tenant, cloud or colocation hosts that run SEV-enabled EPYC systems.
Affected
- AMD EPYC 9004, 7003, 9005, 8004 and 8005 Series Processors
- AMD EPYC Embedded 7003, 8004, 9004 and 9005 Series Processors
- Exact affected firmware versions: unknown; verify against AMD-SB-3038
Fixed in
Unknown. Obtain the fixed firmware/AGESA versions from AMD security bulletin AMD-SB-3038.
Workaround
Unknown. No workaround specific to this CVE has been published in the sources reviewed.
Exploitation
- As of 11 Nov 2026, not known to be exploited.
- No public exploit code indexed in Metasploit or Exploit-DB.
- Not listed in the CISA KEV catalog (early snapshot).
Our recommendation
- Check whether any EPYC hosts with SEV are in use, especially in multi-tenant or hosting environments.
- If affected, plan the BIOS/firmware update through your server vendor once AMD-SB-3038 fixed versions are confirmed.
- Limit hypervisor and host administration rights to a minimum.
- Priority: low to medium for most SMEs.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- AMD Security Bulletin AMD-SB-3038 www.amd.com
- AMD Product Security www.amd.com
- Strix CVE-2026-28247 www.strix.ai
- Threatint CVE-2026-28247 cve.threatint.com
- OffSeq Radar CVE-2026-28247 radar.offseq.com
- Supermicro Security Center www.supermicro.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 14:56.
Original description (NVD)
Improper Access Control Applied to Mirrored or Aliased Memory Regions in AMD Secure Encrypted Virtualization (SEV) firmware could allow a malicious hypervisor to change the encryption bit for guest context pages potentially resulting in loss of integrity.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
Affected? We can help.
We check whether your systems are affected, install updates and close the gap – continuously with the System Health Checker if you wish.