CVE-2021-26349

Guest migration integrity bypass via reused report ID

Published May 11, 2022 · Updated Sep 17, 2024

Improper report handling in AMD SEV-SNP firmware on third-generation EPYC processors allows local users to subvert guest migration trust. When importing a guest, the firmware fails to assign a fresh report ID, so a dishonest Migration Agent can present an identity the guest already trusts. Exploitation requires control of the guest-migration path and affects the integrity of the guest's trust decision rather than confidentiality or availability.

CVSS severity5.5
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper report handling in AMD SEV-SNP firmware on third-generation EPYC processors allows local users to subvert guest migration trust. When importing a guest, the firmware fails to assign a fresh report ID, so a dishonest Migration Agent can present an identity the guest already trusts. Exploitation requires control of the guest-migration path and affects the integrity of the guest's trust decision rather than confidentiality or availability.

The record

CVE
CVE-2021-26349
Published
May 11, 2022
Updated
Sep 17, 2024
Vendor
AMD
Product
AMD EPYC Processors
Classifications
T1557
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 11, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=various

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

AMD · AMD EPYC Processorsversion=various

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
2.1NIST NVDAV:L/AC:L/Au:N/C:N/I:P/A: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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1557Adversary-in-the-Middle

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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