CVE-2021-26348

Memory integrity loss via stale IOMMU mappings

Published May 11, 2022 · Updated Sep 16, 2024

Improper TLB invalidation in 3rd Gen AMD EPYC processors allows local users to cause an I/O device to write unauthorized memory. The IOMMU fails to flush stale Translation Lookaside Buffer entries, so an I/O device retains mappings to memory it should no longer access. Exploitation requires local low-privileged access and can corrupt protected memory, compromising integrity without reported disclosure or service interruption.

CVSS severity5.5
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper TLB invalidation in 3rd Gen AMD EPYC processors allows local users to cause an I/O device to write unauthorized memory. The IOMMU fails to flush stale Translation Lookaside Buffer entries, so an I/O device retains mappings to memory it should no longer access. Exploitation requires local low-privileged access and can corrupt protected memory, compromising integrity without reported disclosure or service interruption.

The record

CVE
CVE-2021-26348
Published
May 11, 2022
Updated
Sep 16, 2024
Vendor
AMD
Product
AMD EPYC Processors
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 11, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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.

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

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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