CVE-2021-26366
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedAn attacker, who gained elevated privileges via some other vulnerability, may be able to read data from Boot ROM resulting in a loss of system integrity.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceThis is a Boot ROM information disclosure vulnerability where an attacker who has already achieved elevated privileges (through a separate vulnerability) can read data from the Boot ROM, compromising system integrity. Boot ROM is the immutable firmware that executes first during system startup, and exposing its contents could reveal sensitive cryptographic material or security mechanisms.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE dataall versionsall versionsall versionsall versionsall versionsall versionsall versionsall versionsCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify AMD hardware in the systemRun 'lspci | grep -i vga' on Linux, check Device Manager on Windows, or visually inspect the system for AMD components such as Ryzen/Athlon processors or Radeon graphicsAffected if The system contains an AMD processor, APU, or graphics card from the affected product list
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Confirm the specific product modelCheck the exact model number of the AMD component via system information tools (such as 'lscpu', 'dmidecode', or CPU-Z on Windows) or the original system/board documentationAffected if The model matches any of: Radeon Software, Athlon 3050ge, Athlon 3150g, Athlon 3150ge, Ryzen 3 2200u, Ryzen 3 2300u, Ryzen 3 3100, or Ryzen 3 3300g
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Check firmware version if accessibleOn systems with UEFI/BIOS access, enter the firmware settings (typically via Del, F2, or F12 during boot) and locate the firmware version information for the processor or system firmwareAffected if The firmware version cannot be updated or is running an older variant of the Boot ROM (this is inherently limited since Boot ROM is immutable and typically not user-viewable)
A system is affected if it contains any of the AMD products listed in the affected products range, since the vulnerability resides in the immutable Boot ROM hardware/firmware and cannot be patched via software updates.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataSince Boot ROM vulnerabilities typically cannot be patched via software updates, mitigation requires a defense-in-depth approach: implement secure boot with hardware root of trust, ensure the primary privilege escalation vulnerability is patched, and consider hardware replacement if the affected component cannot be secured.
- Consultation8.0 h
- Implementation24.0 h
- Testing16.0 h
- Review / QA8.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-26366 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-26366 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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