dbcve.org
Windows 10 1809Operating system · Microsoft

CVE-2025-55233

HIGH · 7.8 CVSS v3.1 Published 2025-12-09
Fix available
A fix is available. Upgrade to 10.0.17763.8146 / 10.0.19044.6691 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

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 · unedited
Out-of-bounds read in Windows Projected File System allows an authorized attacker to elevate privileges 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 confidence

An out-of-bounds read vulnerability exists in the Windows Projected File System (ProjFS) component. This memory safety flaw allows a locally authenticated attacker to read unintended kernel memory, which can be leveraged to elevate privileges from a standard user account to higher system-level permissions.

MitigationApply the Microsoft security update for CVE-2025-55233 via Windows Update or enterprise patch management to remediate the kernel-level vulnerability in Projected File System.

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
Windows 10 1809Operating system
Affected:< 10.0.17763.8146
Windows 10 21h2Operating system
Affected:< 10.0.19044.6691
Windows 10 22h2Operating system
Affected:< 10.0.19045.6691
Windows 11 23h2Operating system
Affected:< 10.0.22631.6345
Windows 11 24h2Operating system
Affected:< 10.0.26100.7392
Windows 11 25h2Operating system
Affected:< 10.0.26200.7392
Windows Server 2019Operating system
Affected:< 10.0.17763.8146
Windows Server 2022Operating system
Affected:< 10.0.20348.4467

CVSS 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
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/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 checks

Work through these to decide whether this CVE applies to you.

  1. Check Windows version and build number
    Open Command Prompt or PowerShell and run: `winver` or `systeminfo | findstr /B /C:"OS Name" /C:"OS Version"` or in PowerShell: `(Get-ComputerInfo).OsVersion`
    Affected if The reported OS version and build number fall below any of the thresholds: 10.0.17763.8146 (1809/Server 2019), 10.0.19044.6691 (21h2), 10.0.19045.6691 (22h2), 10.0.22631.6345 (23h2), 10.0.20348.4467 (Server 2022), 10.0.26100.7392 (24h2), or 10.0.26200.7392 (25h2)
  2. Verify ProjFS feature is enabled
    In PowerShell, run: `Get-WindowsOptionalFeature -Online -FeatureName *ProjFS*` or check the registry at `HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Setup\OptionalFeatures\ProjFS`
    Affected if The ProjFS feature shows as Enabled or the registry value indicates it is turned on
  3. Check if ProjFS driver is loaded
    In an elevated Command Prompt, run: `fltmc filters` or `sc query mrxdav` to see if the ProjFS-related filter driver is active
    Affected if The mrxdav filter or ProjFS-related filter driver is running or loaded in memory
  4. Confirm current kernel build against patch baseline
    Run `winver` to obtain the exact build number, then manually compare against the fixed versions listed in the affected ranges
    Affected if The installed build number is lower than the fixed version for the corresponding Windows release

The system is affected if it runs a Windows version within the affected build ranges AND has the Projected File System (ProjFS) feature enabled or loaded, allowing a local attacker to exploit the out-of-bounds read for privilege escalation.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 10.0.17763.8146 / 10.0.19044.6691 / 10.0.19045.6691 or later
Fixed in 10.0.17763.814610.0.19044.669110.0.19045.6691
Interim mitigation

Apply the Microsoft security update for CVE-2025-55233 via Windows Update or enterprise patch management to remediate the kernel-level vulnerability in Projected File System.

Recommended fix High confidence

Windows 10 1809: build 10.0.17763.8146 | Windows 10 21h2: build 10.0.19044.6691 | Windows 10 22h2: build 10.0.19045.6691 | Windows 11 23h2: build 10.0.22631.6345 | Windows 11 24h2: build 10.0.26100.7392 | Windows 11 25h2: build 10.0.26200.7392 | Windows Server 2019: build 10.0.17763.8146 | Windows S

  1. Check current Windows build version by running `winver` or `systeminfo | findstr /B /C:"OS Name" /C:"OS Version"`
  2. Open Settings > Windows Update > Check for updates
  3. Install all available Windows updates, particularly the security update for this CVE
  4. Verify the installed build version meets or exceeds the minimum fixed version for your Windows release
  5. Alternatively, manually download and install the specific cumulative update from Microsoft Update Catalog matching your Windows version (KB50555233 or similar)
Caveat Standard Windows update deployment - test critical applications before broad rollout; updates may require restart

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Windows 10 1809 Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-55233 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

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.

What belongs here
  • 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