CVE-2021-26329

Resource exhaustion via invalid SMU length

Published Nov 16, 2021 · Updated Sep 16, 2024

Integer overflow in AMD System Management Unit firmware in 1st Gen AMD EPYC Processors allows local users to exhaust resources via invalid lengths. The SMU mishandles an invalid length parameter, causing arithmetic overflow during firmware request processing and a potential loss of resources. Exploitation requires local access to an affected platform; the bounded impact is resource depletion and service disruption, with no disclosed data disclosure or code execution.

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

Integer overflow in AMD System Management Unit firmware in 1st Gen AMD EPYC Processors allows local users to exhaust resources via invalid lengths. The SMU mishandles an invalid length parameter, causing arithmetic overflow during firmware request processing and a potential loss of resources. Exploitation requires local access to an affected platform; the bounded impact is resource depletion and service disruption, with no disclosed data disclosure or code execution.

The record

CVE
CVE-2021-26329
Published
Nov 16, 2021
Updated
Sep 16, 2024
Vendor
AMD
Product
2nd Gen AMD EPYC Processors
Classifications
CWE-130
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 16, 2021CVE 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <RomePI-SP3_1.0.0.C

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

AMD · 2nd Gen AMD EPYC Processorsversion=unspecified <RomePI-SP3_1.0.0.C
AMD · 3rd Gen AMD EPYC Processorsversion=unspecified <MilanPI-SP3_1.0.0.4
AMD · 1st Gen AMD EPYC Processorsversion=unspecified <NaplesPI-SP3_1.0.0.G

Published CVSS scores

5.5[email protected]CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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

CWE-130Improper Handling of Length Parameter Inconsistency

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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