CVE-2021-26346

Service interruption via unchecked bootloader integer operand

Published Jan 10, 2023 · Updated Apr 9, 2025

Integer overflow in AMD AGESA for affected Ryzen processors allows local users to cause denial of service through a crafted SPI-flash L2 table. The AMD Secure Processor bootloader fails to validate an integer operand before processing the L2 directory table in SPI flash, allowing arithmetic wraparound. Low-privileged local access is required; AMD does not specify whether the interruption causes a hang, crash, or reboot.

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

Integer overflow in AMD AGESA for affected Ryzen processors allows local users to cause denial of service through a crafted SPI-flash L2 table. The AMD Secure Processor bootloader fails to validate an integer operand before processing the L2 directory table in SPI flash, allowing arithmetic wraparound. Low-privileged local access is required; AMD does not specify whether the interruption causes a hang, crash, or reboot.

The record

CVE
CVE-2021-26346
Published
Jan 10, 2023
Updated
Apr 9, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-190, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 10, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 9, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5CISA-ADPCVSS: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.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
T1499Endpoint Denial of Service

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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