dbcve.org
Windows 10 1607Operating system · Microsoft

CVE-2026-25178

HIGH · 7.0 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 →
72/100
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
Use after free in Windows Ancillary Function Driver for WinSock 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

A use-after-free vulnerability in the Windows Ancillary Function Driver (AFD.sys) for WinSock allows a locally authorized attacker to execute code with elevated privileges. The vulnerability involves improper memory management in the kernel-mode driver that handles Windows Sockets operations, enabling an attacker to manipulate freed memory and achieve privilege escalation from a low-privileged account to SYSTEM level.

MitigationApply Microsoft security updates for this vulnerability once released; for immediate workarounds, restrict local code execution privileges and monitor for suspicious kernel-level process activity.

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 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 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
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:H/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 against affected ranges
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' and compare the build number to the listed version thresholds
    Affected if The build number is lower than any of these thresholds: 14393.8957, 17763.8511, 19044.7058, 19045.7058, 22631.6783, 26100.7979, 26200.7979, 28000.1719
  2. Verify AFD.sys is present
    Check that the file C:\Windows\System32\drivers\AFD.sys exists on the system
    Affected if The driver file is present and the system version check shows an affected build
  3. Confirm AFD.sys driver version
    Right-click AFD.sys in System32\drivers, go to Properties, Details tab, and check the File Version field
    Affected if The driver version corresponds to an unpatched Windows build from the affected version list

The system is affected if it runs any Windows 10 or 11 version with a build number lower than the fixed versions listed, as the use-after-free in AFD.sys requires an unpatched kernel driver handling WinSock operations.

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 10.0.14393.8957 / 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 Microsoft security updates for this vulnerability once released; for immediate workarounds, restrict local code execution privileges and monitor for suspicious kernel-level process activity.

Recommended fix High confidence

Upgrade to version 10.0.14393.8957 or later for Win10 1607; 10.0.17763.8511 or later for Win10 1809; 10.0.19044.7058 or later for Win10 21h2; 10.0.19045.7058 or later for Win10 22h2; 10.0.22631.6783 or later for Win11 23h2; 10.0.26100.7979 or later for Win11 24h2; 10.0.26200.7979 or later for Win11

  1. 1. Identify the current Windows version by running 'winver' or checking System Properties
  2. 2. Determine which version branch your system is on (1607, 1809, 21h2, 22h2, 23h2, 24h2, 25h2, or 26h1)
  3. 3. Apply the appropriate Windows security update that includes the fix for CVE-2026-25178
  4. 4. For Windows 10 systems: Install the latest cumulative update for your specific version (1607, 1809, 21h2, or 22h2)
  5. 5. For Windows 11 systems: Install the latest cumulative update for your specific version (23h2, 24h2, 25h2, or 26h1)
  6. 6. Restart the system after applying the update
  7. 7. Verify the update was installed successfully by checking Windows Update history
Caveat Standard Windows update risks: update may require restart, verify compatibility with existing software

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
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,120
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,392.

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-2026-25178 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