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Windows 10 1607Operating system · Microsoft

CVE-2026-26128

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 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
Improper authentication in Windows SMB Server 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

This is a local privilege escalation vulnerability in Windows SMB Server stemming from improper authentication. An attacker who already has authorized access to the system can exploit the authentication flaw in SMB to elevate their privileges to a higher level locally.

MitigationApply the appropriate Microsoft security updates for Windows SMB Server to address the improper authentication vulnerability. Verify SMB functionality continues to work correctly after patching.

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
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 build version
    Run 'winver' or 'systeminfo' and note the OS Build number shown (e.g., 19045.7058)
    Affected if The build number is lower than any of these thresholds: 14393.8957 (Win10 1607), 17763.8511 (Win10 1809), 19044.7058 (Win10 21h2), 19045.7058 (Win10 22h2), 22631.6783 (Win11 23h2), 26100.7979 (Win11 24h2), 26200.7979 (Win11 25h2), or 28000.1719 (Win11 26h1)
  2. Verify SMB Server service is running
    Open Services (services.msc) and check the status of 'Server' (SMB 1.x) or run 'Get-Service LanmanServer' in PowerShell
    Affected if The Server service is running (required for SMB to be active)
  3. Confirm SMB is enabled
    Run 'Get-SmbServerConfiguration | Select-Object EnableSMB1Protocol,EnableSMB2Protocol' in PowerShell
    Affected if Either SMB1 or SMB2 is enabled (the vulnerability is in SMB Server authentication)
  4. Check SMB listening status
    Run 'netstat -an | findstr "445"' to verify the SMB port is listening, or run 'Get-SmbConnection' to list active SMB sessions
    Affected if Port 445 is listening and SMB connections are possible

You are affected if your Windows build version is lower than the thresholds listed AND SMB Server is enabled and listening on your system.

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 the appropriate Microsoft security updates for Windows SMB Server to address the improper authentication vulnerability. Verify SMB functionality continues to work correctly after patching.

Recommended fix High confidence

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 | Windows 11 26h1 to 10.0.28000.1719

  1. Identify the current Windows version by running 'winver' or checking System Properties
  2. Determine which affected version category your system falls under (Windows 10 1607, 1809, 21h2, 22h2, or Windows 11 23h2, 24h2, 25h2, 26h1)
  3. Open Settings > Update & Security > Windows Update
  4. Click 'Check for updates' to download and install the latest security updates
  5. Alternatively, manually download and install the appropriate Cumulative Security Update from the Microsoft Update Catalog for your specific Windows version
  6. Verify the update was installed successfully and restart the system if prompted
  7. Confirm the build number matches or exceeds the fixed version for your Windows release (e.g., Windows 10 22h2 should be 10.0.19045.7058 or higher)
Caveat Standard Windows update risks apply - ensure backups exist and plan for potential restart; enterprise deployments should test in staging first

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

Fix this in Windows 10 1607 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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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-2026-26128 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