CVE-2026-21222
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 · uneditedInsertion of sensitive information into log file in Windows Kernel allows an authorized attacker to disclose information locally.
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 confidenceWindows Kernel contains a vulnerability where sensitive information is being written to log files, allowing a local authorized attacker to retrieve information they should not have access to. This is an information disclosure flaw via log injection or improper log handling in the Windows kernel component.
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 data< 10.0.14393.8868< 10.0.17763.8389< 10.0.19044.6937< 10.0.19045.6937< 10.0.22631.6649< 10.0.26100.7781= r2< 10.0.14393.8868CVSS 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
- None
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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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Check Windows build versionRun 'winver' or 'systeminfo | findstr /B /C:"OS Version"' or 'ver' command in Command Prompt to obtain the full version and build numberAffected if The build number is lower than the fixed version for your Windows release (10.0.14393.8868 for 1607/Server 2016, 10.0.17763.8389 for 1809, 10.0.19044.6937 for 21h2, 10.0.19045.6937 for 22h2, 10.0.22631.6649 for 11 23h2, 10.0.26100.7781 for 11 24h2, or if running Server 2012 R2)
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.
dbcve · scoped10.0.14393.886810.0.17763.838910.0.19044.6937
Apply Microsoft security updates for Windows when released. Until a patch is available, restrict access to system logs and monitor for unauthorized access to log files.
Apply the Microsoft security update containing the fix for CVE-2026-21222, which raises the Windows build to the fixed version number for each affected release (e.g., 10.0.14393.8868 for Windows 10 1607/Server 2016, 10.0.17763.8389 for Windows 10 1809, etc.)
- Identify the current Windows version and build number by running 'winver' or 'systeminfo'
- Navigate to Windows Update Settings > Check for updates
- Install all available security updates, specifically looking for the KB patch corresponding to this CVE (typically released as part of Microsoft's monthly security updates)
- For enterprise environments, deploy updates via Windows Server Update Services (WSUS) or Microsoft Endpoint Configuration Manager
- After installation, verify the build number matches or exceeds the fixed version for your Windows release: Windows 10 1607 should be 10.0.14393.8868 or later; Windows 10 1809 should be 10.0.17763.8389 or later; Windows 10 21h2 should be 10.0.19044.6937 or later; Windows 10 22h2 should be 10.0.19045.6937 or later; Windows 11 23h2 should be 10.0.22631.6649 or later; Windows 11 24h2 should be 10.0.26
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation1.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-21222 — 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-2026-21222 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
- No spam, self-promotion, credentials, or personal data