CVE-2023-20585

Guest integrity loss via unchecked IOMMU write

Published Apr 16, 2026 · Updated Apr 16, 2026

Out-of-bounds write in the IOMMU on affected AMD EPYC processors allows attackers with hypervisor privileges to corrupt SNP guest data. During host buffer access, insufficient RMP checks let the IOMMU write beyond the supplied buffer length without enforcing protected guest memory boundaries. Exploitation requires local high privileges and a compromised hypervisor; confidentiality and availability impacts are not reported.

CVSS severity5.3
Medium
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in the IOMMU on affected AMD EPYC processors allows attackers with hypervisor privileges to corrupt SNP guest data. During host buffer access, insufficient RMP checks let the IOMMU write beyond the supplied buffer length without enforcing protected guest memory boundaries. Exploitation requires local high privileges and a compromised hypervisor; confidentiality and availability impacts are not reported.

The record

CVE
CVE-2023-20585
Published
Apr 16, 2026
Updated
Apr 16, 2026
Vendor
Advanced Micro Devices, Inc.
Product
AMD EPYC Embedded 7003 Series Processors
Classifications
CWE-788, T1565
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Apr 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Advanced Micro Devices, Inc. · AMD EPYC Embedded 7003 Series ProcessorsAffected versions are unavailable in this record.
Advanced Micro Devices, Inc. · AMD EPYC Embedded 9004 Series ProcessorsAffected versions are unavailable in this record.
Advanced Micro Devices, Inc. · AMD EPYC™ 9004 Series ProcessorsAffected versions are unavailable in this record.
Advanced Micro Devices, Inc. · AMD EPYC™ 7003 Series ProcessorsAffected versions are unavailable in this record.

Published CVSS scores

5.6Advanced Micro Devices Inc.CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:N
5.3Advanced Micro Devices Inc.CVSS:4.0/AV:L/AC:H/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-788Access of Memory Location After End of Buffer
T1565Data Manipulation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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