dbcve.org
Windows 10 1809Operating system · Microsoft

CVE-2025-55336

MEDIUM · 5.5 CVSS v3.1 Published 2025-10-14
Fix available
A fix is available. Upgrade to 10.0.17763.7919 / 10.0.19044.6456 or later.
See remediation →
57/100
Remediation priority · Elevated
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
Exposure of sensitive information to an unauthorized actor in Windows Cloud Files Mini Filter Driver 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 confidence

This is a local information disclosure vulnerability in the Windows Cloud Files Mini Filter Driver. An authorized attacker with local access can exploit this to disclose sensitive information due to improper handling of data within the driver. The vulnerability has low attack complexity and requires local access but no privileges, scoring 5.5 on the CVSS scale.

MitigationApply the Microsoft security update for CVE-2025-55336 via Windows Update or the Microsoft Update Catalog to patch the Cloud Files Mini Filter Driver.

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:< 10.0.17763.7919
Windows 10 21h2Operating system
Affected:< 10.0.19044.6456
Windows 10 22h2Operating system
Affected:< 10.0.19045.6456
Windows 11 22h2Operating system
Affected:< 10.0.22621.6060
Windows 11 23h2Operating system
Affected:< 10.0.22631.6060
Windows 11 24h2Operating system
Affected:< 10.0.26100.6899
Windows 11 25h2Operating system
Affected:< 10.0.26200.6899
Windows Server 2019Operating system
Affected:< 10.0.17763.7919

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
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 checks

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

  1. Verify Cloud Files Mini Filter Driver is present
    Run 'fltmc.exe filters' from an elevated command prompt or use 'Get-Command' to locate the driver in the Windows\System32\drivers directory. The driver file is typically named CldFlt.sys.
    Affected if The Cloud Files Mini Filter Driver (CldFlt.sys) is loaded on the system.
  2. Obtain the driver file version
    Run 'Get-ItemProperty -Path C:\Windows\System32\drivers\CldFlt.sys | Select-Object VersionInfo' in PowerShell, or right-click the driver file, select Properties, and view the Details tab for the File Version.
    Affected if Unable to retrieve version information for CldFlt.sys.
  3. Compare driver version against affected ranges
    Match the obtained File Version against these thresholds: Windows 10 1809/Server 2019: 10.0.17763.7919; Windows 10 21h2: 10.0.19044.6456; Windows 10 22h2: 10.0.19045.6456; Windows 11 22h2: 10.0.22621.6060; Windows 11 23h2: 10.0.22631.6060; Windows 11 24h2: 10.0.26100.6899; Windows 11 25h2: 10.0.26200.6899.
    Affected if The installed driver version is lower than the corresponding threshold for your Windows version.
  4. Confirm Windows version for context
    Run 'winver.exe' or 'Get-ComputerInfo | Select-Object WindowsProductName, WindowsVersion, OsHardwareAbstractionLayer' in PowerShell to identify the exact Windows build and version.
    Affected if Windows version is one of the affected releases listed in the CVE but the driver version cannot be determined or verified.

The system is affected if the Cloud Files Mini Filter Driver (CldFlt.sys) is present and its version is lower than the specific threshold for the installed Windows build.

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 10.0.17763.7919 / 10.0.19044.6456 / 10.0.19045.6456 or later
Fixed in 10.0.17763.791910.0.19044.645610.0.19045.6456
Interim mitigation

Apply the Microsoft security update for CVE-2025-55336 via Windows Update or the Microsoft Update Catalog to patch the Cloud Files Mini Filter Driver.

Recommended fix High confidence

Windows 10 1809/Server 2019: build 10.0.17763.7919 or later | Windows 10 21h2: build 10.0.19044.6456 or later | Windows 10 22h2: build 10.0.19045.6456 or later | Windows 11 22h2: build 10.0.22621.6060 or later | Windows 11 23h2: build 10.0.22631.6060 or later | Windows 11 24h2: build 10.0.26100.6899

  1. Identify the installed Windows version by running 'winver' or checking System Properties
  2. Determine the current build number (e.g., 10.0.17763.x for Windows 10 1809/Server 2019)
  3. Open Windows Update by navigating to Settings > Update & Security > Windows Update
  4. Click 'Check for updates' to download and install the latest security update
  5. Alternatively, manually download the specific security update from the Microsoft Update Catalog matching your Windows version (KB references can be found on msrc.microsoft.com)
  6. After installation, restart the system when prompted
  7. Verify the build number has updated to the fixed version (e.g., 10.0.17763.7919 or higher for Windows 10 1809/Server 2019)
Caveat None expected; this is a routine security update with no known compatibility issues

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

Fix this in Windows 10 1809 Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,920
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Scan for this in your stack

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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-2025-55336 in production — separate from our analysis above.

No notes yet

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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