CVE-2026-20923
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 · uneditedUse after free in Windows Management Services allows an authorized attacker to elevate privileges locally.
In the news
Third-party coverage- Microsoft CVE Summary - Bleeping Computer
- Microsoft January 2026 Patch Tuesday fixes 3 zero-days, 114 flaws
Surfaced from public web coverage — external links open in a new tab.
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 confidenceA use-after-free vulnerability exists in Windows Management Services where memory is accessed after it has been freed, allowing a locally authorized attacker to execute code with elevated privileges. This is a memory corruption issue in a Windows system 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< 10.0.17763.8276< 10.0.19044.6809< 10.0.19045.6809< 10.0.22631.6491< 10.0.26100.7623< 10.0.26200.7623< 10.0.17763.8276< 10.0.20348.4648CVSS 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
- High
- Privileges
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/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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Check Windows build versionRun 'winver' or 'systeminfo | findstr /C:"Build"' to obtain the OS build numberAffected if The build number is below the threshold for your Windows version (17763.8276 for 1809/Server 2019, 19044.6809 for 21h2, 19045.6809 for 22h2, 22631.6491 for 11 23h2, 26100.7623 for 11 24h2, 26200.7623 for 11 25h2, or 20348.4648 for Server 2022)
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Identify Windows version and buildRun 'systeminfo' or 'winver' to confirm both the Windows release (such as 10 1809, 10 21h2, 11 23h2, Server 2019, Server 2022) and the full build numberAffected if The detected version and build combination matches an affected range and is less than the fixed build number for that release
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Verify Windows Management Services statusRun 'Get-Service Winmgmt' in PowerShell or check the Windows Management Instrumentation service in services.mscAffected if The Windows Management Services (WMI) service is running or set to start automatically, making the vulnerable component active on the system
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Confirm vulnerability applicabilityReview the installed Windows Management Services component version via 'wmic product get name,version' or check the WMI repository version if exposedAffected if The component version corresponds to an unpatched build that falls within the affected version ranges
You are affected if your Windows build number is lower than the specified threshold for your Windows version AND Windows Management Services is enabled on your system.
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 · scoped10.0.17763.827610.0.19044.680910.0.19045.6809
Apply the relevant Microsoft security patch for Windows Management Services once released, and ensure systems are updated through standard Windows Update or enterprise patch management processes.
Windows 10 1809: 10.0.17763.8276 or later | Windows 10 21h2: 10.0.19044.6809 or later | Windows 10 22h2: 10.0.19045.6809 or later | Windows 11 23h2: 10.0.22631.6491 or later | Windows 11 24h2: 10.0.26100.7623 or later | Windows 11 25h2: 10.0.26200.7623 or later | Windows Server 2019: 10.0.17763.8276
- Identify the current Windows build version by running 'winver' or 'systeminfo' in Command Prompt
- Determine which Windows version (10 1809, 10 21h2, 10 22h2, 11 23h2, 11 24h2, 11 25h2, Server 2019, or Server 2022) is installed
- Open Settings > Update & Security > Windows Update and check for updates
- Install all available updates, particularly the security update for CVE-2026-20923
- Alternatively, manually download and install the specific KB patch from the Microsoft Update Catalog matching your Windows version and build
- Restart the system after applying updates
- Verify the build number has been updated to the fixed version or higher using 'winver'
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation6.0 h
- Implementation4.0 h
- Testing10.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,624.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-20923 — 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-2026-20923 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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