CVE-2021-26366

Boot ROM data disclosure to privileged local users

Published May 12, 2022 · Updated Sep 17, 2024

Information disclosure in AMD Ryzen and Athlon Series processors allows local users with elevated privileges to read data from Boot ROM. AMD has not published the defective component or operation that permits the Boot ROM read. Exploitation requires elevated privileges obtained through another vulnerability, and the disclosed consequence is exposure of Boot ROM data with loss of integrity.

CVSS severity7.1
High
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in AMD Ryzen and Athlon Series processors allows local users with elevated privileges to read data from Boot ROM. AMD has not published the defective component or operation that permits the Boot ROM read. Exploitation requires elevated privileges obtained through another vulnerability, and the disclosed consequence is exposure of Boot ROM data with loss of integrity.

The record

CVE
CVE-2021-26366
Published
May 12, 2022
Updated
Sep 17, 2024
Vendor
AMD
Product
AMD Ryzen Series
Classifications
T1005
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. May 12, 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 privilegesadmin

What is affected?

AMD · AMD Ryzen Seriesversion=various
AMD · AMD Athlon Seriesversion=various

Published CVSS scores

7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
3.6NIST NVDAV:L/AC:L/Au:N/C:P/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1005Data from Local System

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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