dbcve.org
Windows 10 1607Operating system · Microsoft

CVE-2026-45599

HIGH · 8.1 CVSS v3.1 Published 2026-06-09
Fix available
A fix is available. Upgrade to 10.0.14393.9234 / 10.0.17763.8880 or later.
See remediation →
90/100
Remediation priority · Urgent
Remotely reachable No privileges 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 Universal Plug and Play (upnp.dll) allows an unauthorized attacker to execute code over a network.

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 exists in the Universal Plug and Play service (upnp.dll) that allows an unauthenticated attacker to achieve remote code execution by exploiting improper memory handling in the UPnP component. The vulnerability is network-exploitable, meaning an attacker can trigger it remotely without prior authentication.

MitigationApply vendor security updates for the affected Windows version immediately. As an interim measure, disable the UPnP service if not required, or block UPnP traffic at the network perimeter. Network segmentation can limit exposure to untrusted segments.

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:< 10.0.14393.9234
Windows 10 1809Operating system
Affected:< 10.0.17763.8880
Windows 10 21h2Operating system
Affected:< 10.0.19044.7417
Windows 10 22h2Operating system
Affected:< 10.0.19045.7417
Windows 11 23h2Operating system
Affected:< 10.0.22631.7219
Windows 11 24h2Operating system
Affected:< 10.0.26100.8655
Windows 11 25h2Operating system
Affected:< 10.0.26200.8655
Windows 11 26h1Operating system
Affected:< 10.0.28000.2269

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
Network
Complexity
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:H/PR:N/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 your Windows version
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to identify the installed Windows version and build number
    Affected if The build number falls below any of these thresholds: 14393.9234 (Win10 1607), 17763.8880 (Win10 1809), 19044.7417 (Win10 21h2), 19045.7417 (Win10 22h2), 22631.7219 (Win11 23h2), 26100.8655 (Win11 24h2), 26200.8655 (Win11 25h2), or 28000.2269 (Win11 26h1)
  2. Verify UPnP service status
    Run 'Get-Service upnphost' in PowerShell or check Services.msc for the 'UPnP Device Host' service
    Affected if The upnphost service is running or set to Automatic start
  3. Check if SSDP discovery is active
    Run 'netsh interface portproxy show all' or inspect active listening ports for SSDP (UDP port 1900) using 'netstat -an | findstr :1900'
    Affected if The system is listening on UDP port 1900 for SSDP discovery packets
  4. Locate and note the upnp.dll version
    Find the file at C:\Windows\System32\upnp.dll, right-click and view Properties, or run 'powershell (Get-Item C:\Windows\System32\upnp.dll).VersionInfo.FileVersion'
    Affected if The DLL exists on the system and the version is not known to be patched; compare the version string against Microsoft's security update releases for this CVE

You are affected if your Windows build number is below the thresholds listed AND the UPnP Device Host service is running and listening for SSDP traffic.

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 10.0.14393.9234 / 10.0.17763.8880 / 10.0.19044.7417 or later
Fixed in 10.0.14393.923410.0.17763.888010.0.19044.7417
Interim mitigation

Apply vendor security updates for the affected Windows version immediately. As an interim measure, disable the UPnP service if not required, or block UPnP traffic at the network perimeter. Network segmentation can limit exposure to untrusted segments.

Recommended fix High confidence

Install Windows security update from Microsoft Update containing the fix for CVE-2026-45599

  1. Check current Windows version by running 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"'
  2. Open Windows Settings > Update & Security > Windows Update
  3. Click 'Check for updates' to download and install the latest security updates
  4. Ensure the installed build number meets or exceeds the minimum fixed version for your Windows release
  5. Alternatively, manually download the specific security update from the Microsoft Update Catalog (catalog.update.microsoft.com) using the KB number corresponding to this CVE
  6. After installation, restart the system to apply the patch
  7. Verify the fix by checking that the installed version now matches or exceeds: 10.0.14393.9234 (Win10 1607), 10.0.17763.8880 (Win10 1809), 10.0.19044.7417 (Win10 21h2), 10.0.19045.7417 (Win10 22h2), 10.0.22631.7219 (Win11 23h2), 10.0.26100.8655 (Win11 24h2), 10.0.26200.8655 (Win11 25h2), or 10.0.28000.2269 (Win11 26h1)
Caveat Standard Windows security update with minimal risk; may require system restart

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
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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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-2026-45599 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