CVE-2026-20853
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 · uneditedConcurrent execution using shared resource with improper synchronization ('race condition') in Windows WalletService allows an unauthorized 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 race condition vulnerability exists in Windows WalletService where improper synchronization of shared resources allows an unauthenticated local attacker to elevate privileges. The vulnerability stems from concurrent execution issues in the WalletService component, likely due to missing or inadequate locking mechanisms around privileged operations.
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< 10.0.14393.8783< 10.0.17763.8276< 10.0.19044.6809< 10.0.19045.6809< 10.0.22631.6491< 10.0.26100.7623< 10.0.26200.7623CVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/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 version against affected rangesRun 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to get the exact Windows build number. Compare the build number to the affected ranges: Windows 10 1607 < 10.0.14393.8783, Windows 10 1809 < 10.0.17763.8276, Windows 10 21h2 < 10.0.19044.6809, Windows 10 22h2 < 10.0.19045.6809, Windows 11 23h2 < 10.0.22631.6491, Windows 11 24h2 < 10.0.26100.7623, Windows 11 25h2 < 10.0.26200.7623Affected if The installed Windows build number falls within any of the unpatched version ranges listed
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Verify WalletService presenceRun 'Get-Service -Name WalletService' in PowerShell or check 'HKLM\SYSTEM\CurrentControlSet\Services\WalletService' in the registry to confirm WalletService is installed on the systemAffected if WalletService exists on the system
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Check WalletService running statusRun 'Get-Process -Name WalletService' or 'tasklist | findstr WalletService' to see if the service is currently runningAffected if WalletService process is active on the system
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Identify local user privilegesRun 'whoami /groups' to list current user group memberships. This vulnerability requires a local user account to exploit the race conditionAffected if The current user is a local user with limited privileges (not an administrator)
A system is affected if it runs a Windows version below the patched builds AND has WalletService installed and running, allowing a local authenticated user to potentially exploit the race condition for privilege escalation.
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 · scoped10.0.14393.878310.0.17763.827610.0.19044.6809
Apply vendor-provided security patches for Windows WalletService. In the interim, restrict local user access to the WalletService and monitor for suspicious process activity. Ensure systems are updated once the patch is released.
Windows 10 1607: 10.0.14393.8783+ | Windows 10 1809: 10.0.17763.8276+ | Windows 10 21h2: 10.0.19044.6809+ | Windows 10 22h2: 10.0.19045.6809+ | Windows 11 23h2: 10.0.22631.6491+ | Windows 11 24h2: 10.0.26100.7623+ | Windows 11 25h2: 10.0.26200.7623+
- 1. Verify current Windows version by running 'winver' or 'systeminfo'
- 2. Check if your current version is below the fixed version for your Windows release
- 3. Open Settings > Windows Update > Check for updates
- 4. Install all available security updates, particularly those released after the vulnerability disclosure
- 5. Restart the system when prompted
- 6. Verify the patch installation by checking Windows Update history for the security update containing CVE-2026-20853
- 7. Alternatively, manually download the specific security update from Microsoft Update Catalog matching your Windows version
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 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 $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-20853 — 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-2026-20853 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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- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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