Windows 10 1607Operating system · Microsoft

CVE-2026-25174

HIGH · 7.8 CVSS v3.1 Published 2026-03-10

Fix available

A fix is available. Upgrade to 10.0.14393.8957 / 10.0.17763.8511 or later.

See remediation →

80/100

Remediation priority · High

Zero-click

Official description

NVD · unedited

Out-of-bounds read in Windows Extensible File Allocation allows an authorized attacker to elevate privileges locally.

Technical summary

dbcve analysis · moderate confidence

An out-of-bounds read vulnerability exists in Windows Extensible File Allocation that allows a locally authenticated attacker to read unintended memory contents and leverage this to elevate privileges to SYSTEM level.

MitigationApply the relevant Microsoft security patch for Windows Extensible File Allocation when available, or implement least-privilege policies to limit local access to sensitive resources.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions

NVD · CPE data

Windows 10 1607Operating system

Affected:< 10.0.14393.8957

Windows 10 1809Operating system

Affected:< 10.0.17763.8511

Windows 10 21h2Operating system

Affected:< 10.0.19044.7058

Windows 10 22h2Operating system

Affected:< 10.0.19045.7058

Windows 11 23h2Operating system

Affected:< 10.0.22631.6783

Windows 11 24h2Operating system

Affected:< 10.0.26100.7979

Windows 11 25h2Operating system

Affected:< 10.0.26200.7979

Windows 11 26h1Operating system

Affected:< 10.0.28000.1719

CVSS breakdown

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?

dbcve checks

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

Check Windows build version

Run 'winver' or 'systeminfo | findstr /B /C:"OS Version"' and note the build number (e.g., 10.0.19045.xxxx)

Affected if The build number falls below any of these thresholds: 14393.8957 (1607), 17763.8511 (1809), 19044.7058 (21h2), 19045.7058 (22h2), 22631.6783 (23h2), 26100.7979 (24h2), 26200.7979 (25h2), 28000.1719 (26h1)
Confirm Windows edition matches affected range

Run 'systeminfo' and note the OS Name and OS Configuration - this affects Windows 10 and Windows 11 specifically

Affected if Running Windows 10 1607/1809/21h2/22h2 or Windows 11 23h2/24h2/25h2/26h1 with a build number below the thresholds above
Identify if exFAT or Extensible File Allocation driver is present

Check for the presence of exFAT-related system drivers: look for 'ufsd.sys' in System32\drivers or check driver list with 'driverquery /v | findstr -i exfat'

Affected if The exFAT filesystem driver (ufsd.sys) or Windows Extensible File Allocation driver is installed on the system
Verify current user context

Run 'whoami /groups' and check if you are in the Administrators group or have limited user privileges

Affected if You have local user access (authenticated local user) - the attacker needs local authentication to exploit this vulnerability

You are affected if you run any of the listed Windows 10/11 versions with a build number below the specified threshold AND have the Extensible File Allocation component (exFAT driver) present on your system.

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

Remediation

dbcve · scoped

Upgrade available Upgrade to 10.0.14393.8957 / 10.0.17763.8511 / 10.0.19044.7058 or later

Fixed in 10.0.14393.895710.0.17763.851110.0.19044.7058

Interim mitigation

Apply the relevant Microsoft security patch for Windows Extensible File Allocation when available, or implement least-privilege policies to limit local access to sensitive resources.

Recommended fix High confidence

Upgrade to the following fixed builds: Windows 10 1607 to 10.0.14393.8957, Windows 10 1809 to 10.0.17763.8511, Windows 10 21h2 to 10.0.19044.7058, Windows 10 22h2 to 10.0.19045.7058, Windows 11 23h2 to 10.0.22631.6783, Windows 11 24h2 to 10.0.26100.7979, Windows 11 25h2 to 10.0.26200.7979, or Window

Check the current Windows version by opening Command Prompt and running 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"'
Identify which Windows version and build you are currently running from the list of affected versions above
Open Windows Settings and navigate to Windows Update, or manually download the appropriate security update from the Microsoft Update Catalog (catalog.update.microsoft.com)
Install the security update corresponding to your Windows version: For Windows 10 1607 upgrade to 10.0.14393.8957, for Windows 10 1809 upgrade to 10.0.17763.8511, for Windows 10 21h2 upgrade to 10.0.19044.7058, for Windows 10 22h2 upgrade to 10.0.19045.7058, for Windows 11 23h2 upgrade to 10.0.22631.6783, for Windows 11 24h2 upgrade to 10.0.26100.7979, for Windows 11 25h2 upgrade to 10.0.26200.797
Restart the computer when prompted to complete the installation
Verify the update was applied by checking the Windows version again to confirm it matches or exceeds the fixed build number

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

Fix this in Windows 10 1607 Scoped from the published advisory

Consultation4.0 h
Implementation16.0 h
Testing8.0 h
Review / QA4.0 h

32.0 hours of engineering $5,600

Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,960.

Scan for this in your stack

Free · runs locally

dbcve dependency scanner

Check whether your project pulls in CVE-2026-25174 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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References

Primary sources

msrc.microsoft.comVendor Advisory
nvd.nist.govNVD record

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-25174 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2026-25174?

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

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

At a glance

A fix existsUpgrade to 10.0.14393.8957 / 10.0.17763.8511 or later

Severity 7.8 High

Exploit likelihood EPSS, next 30 days 0.3%

Affects: Windows 10 1607

Remediation

A high-priority fix

Fix this in Windows 10 1607 32 hrs · Moderate

Typical engagement from $5,600

Get a fix See the full breakdown ↓

A high-priority vulnerability. Send your environment and a specialist will scope CVE-2026-25174 and return a fixed quote and timeline.

You’ll deal with our team directly and deploy the reviewed fix to staging first — never straight to production.

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.

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.

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.

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.

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.

Check your environment

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.

Scan for this in your stack

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

Practitioner notes

No notes yet

Official description

Technical summary

Affected products & versions

CVSS breakdown

Am I affected?

Remediation

References