CVE-2021-26341
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 · uneditedSome AMD CPUs may transiently execute beyond unconditional direct branches, which may potentially result in data leakage.
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 speculative execution vulnerability in AMD CPUs where the processor may transiently execute instructions beyond unconditional direct branches. This could allow an attacker to leak sensitive data through timing side-channel attacks, similar to Spectre-class vulnerabilities.
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
- Changed
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/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 your CPU modelRun 'wmic cpu get name' on Windows or 'cat /proc/cpuinfo' on Linux to view the processor nameAffected if The CPU model is one of: Athlon X4 940, Athlon X4 950, Athlon X4 970, Athlon X4 835, Athlon X4 845, Athlon X4 830, Athlon X4 840, or Athlon X4 860k
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Verify firmware versionCheck BIOS/UEFI version information via system firmware setup or tools like 'dmidecode -s bios-version' on LinuxAffected if Any firmware version is present on an affected CPU model (all versions are vulnerable)
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Confirm microcode loadedOn Linux, check 'dmesg | grep -i microcode' or 'cat /proc/cpuinfo' for microcode version. On Windows, use 'wmic baseboard get version' or check BIOS infoAffected if The system is running without updated microcode that includes CVE-2021-26341 fixes
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Check speculative execution mitigationsReview BIOS/UEFI settings for options like 'Speculative Store Bypass', 'Branch Prediction', or 'Spectre/Meltdown mitigations' and confirm they are enabledAffected if Hardware-level mitigations are disabled or not available in BIOS
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Verify OS-level Spectre mitigationsOn Linux, check 'cat /sys/devices/system/cpu/vulnerabilities/*'. On Windows, run 'Get-MpComputerStatus' and check 'AntivirusEnabled' or review Windows Spectre variant statusAffected if Operating system security updates for speculative execution are not installed
You are affected if your system uses any AMD Athlon X4 model listed (940, 950, 970, 835, 845, 830, 840, or 860k), as all firmware versions of these processors are vulnerable to CVE-2021-26341.
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 AMD CPU microcode updates and relevant OS/security patches. Consult AMD's processor security advisories for specific CPU model guidance and enable any available hardware-level mitigations.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,888.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-26341 — 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-2021-26341 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
- No spam, self-promotion, credentials, or personal data