CVE-2021-26365
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 · uneditedCertain size values in firmware binary headers could trigger out of bounds reads during signature validation, leading to denial of service or potentially limited leakage of information about out-of-bounds memory contents.
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 confidenceOut of bounds read vulnerability in firmware signature validation where maliciously crafted size values in binary headers are not properly validated before use, allowing reads beyond buffer boundaries leading to potential DoS or limited memory disclosure.
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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
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 your CPU modelUse system information tools (such as 'lscpu' on Linux, 'systeminfo' on Windows, or check BIOS/UEFI setup) to determine the exact processor model numberAffected if The CPU model matches any of these: Ryzen 5 2400g, Ryzen 5 2400ge, Ryzen 3 2200ge, Ryzen 3 2200g, Ryzen 3 Pro 2100ge, Ryzen 9 5900x, Ryzen 9 5950x, or Ryzen 9 5900
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Locate firmware or BIOS versionAccess the BIOS/UEFI setup during boot (press Delete, F2, or other vendor-specific key) or use OS tools like 'dmidecode -s bios-version' on Linux or 'wmic bios get smbiosbiosversion' on WindowsAffected if You are unable to confirm that your firmware has been updated with the vendor fix for CVE-2021-26365 signature validation bounds checking
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Verify firmware update statusCheck the AMD vendor website or your motherboard/OEM vendor support page for your specific hardware to find firmware release notes mentioning CVE-2021-26365 or signature validation fixesAffected if The installed firmware version predates or lacks the security update that addresses the out-of-bounds read in signature validation
You are affected if your system uses one of the listed AMD Ryzen processor models and the installed firmware version has not received the vendor update that adds proper bounds checking for header size fields in binary signature validation.
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 dataApply vendor firmware updates that修正 signature validation code to properly validate and bounds-check header size fields before reading data.
- Consultation6.0 h
- Implementation16.0 h
- Testing12.0 h
- Review / QA8.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $11,712.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-26365 — 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-2021-26365 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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- 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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