CVE-2021-26347

Service interruption via bootloader integer overflow

Published May 11, 2022 · Updated Aug 3, 2024

Integer overflow in the ASP bootloader on AMD Ryzen 5000 Series allows local users to interrupt service via a crafted operand. The bootloader fails to validate the operand before using it to build the L2 directory table in SPI flash, allowing arithmetic wraparound. Low-privileged local access and a high-complexity trigger are required; the published impact is limited to availability, without a defined hang or crash mode.

CVSS severity4.7
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Integer overflow in the ASP bootloader on AMD Ryzen 5000 Series allows local users to interrupt service via a crafted operand. The bootloader fails to validate the operand before using it to build the L2 directory table in SPI flash, allowing arithmetic wraparound. Low-privileged local access and a high-complexity trigger are required; the published impact is limited to availability, without a defined hang or crash mode.

The record

CVE
CVE-2021-26347
Published
May 11, 2022
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-1284, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 11, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record 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 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

4.7NIST NVDAV:L/AC:M/Au:N/C:N/I:N/A:C
4.7NIST NVDCVSS:3.1/AV:L/AC:H/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-1284Improper Validation of Specified Quantity in Input
T1499.004Application or System Exploitation

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo