CVE-2025-48821
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 · uneditedUse after free in Windows Universal Plug and Play (UPnP) Device Host allows an authorized attacker to elevate privileges over an adjacent 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 confidenceA use-after-free vulnerability exists in the Windows Universal Plug and Play (UPnP) Device Host service. This memory corruption flaw allows an authenticated attacker on an adjacent network (e.g., same LAN or WiFi) to execute code with elevated privileges by exploiting the dangling pointer after memory is freed.
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< 10.0.10240.21073< 10.0.14393.8246< 10.0.17763.7558< 10.0.19044.6093< 10.0.19045.6093< 10.0.22621.5624< 10.0.22631.5624< 10.0.26100.4652CVSS 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
- Adjacent
- Complexity
- High
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:A/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 checksWork through these to decide whether this CVE applies to you.
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Check if the UPnP Device Host service is runningOpen Services (services.msc) and look for 'UPnP Device Host' or run 'Get-Service upnphost' in PowerShell. If the service is stopped or disabled, the vulnerability cannot be exploited.Affected if The UPnP Device Host service is running and set to Automatic or Manual startup
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Verify the installed Windows versionRun 'winver' from the Run dialog or use 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' in Command Prompt. Compare the full build number (e.g., 10.0.19045.6093) against the affected version ranges listed in the CVE.Affected if The Windows build number falls below any of the thresholds: 10240.21073 (1507), 14393.8246 (1607), 17763.7558 (1809), 19044.6093 (21h2), 19045.6093 (22h2), 22621.5624 (11 22h2), 22631.5624 (11 23h2), 26100.4652 (11 24h2)
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Check if UPnP is enabled on the systemOpen Control Panel > Network and Internet > Network and Sharing Center > Media Streaming Options, or check the registry under HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Shell Extensions\Blocked for UPnP-related settings. Alternatively, verify UPnP is active via router or firewall configuration.Affected if UPnP is enabled and accessible from the local network (the attack requires network adjacency)
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Confirm network exposure of UPnP serviceRun 'netsh interface portproxy show all' or use 'netstat -an | findstr "1900"' (UPnP default port) to check if port 1900 (SSDP) and other UPnP ports are listening on network interfaces. Verify firewall rules with 'Get-NetFirewallRule -DisplayName "UPnP*"' in PowerShell.Affected if UPnP ports are open to the local network segment without proper network segmentation or firewall restrictions
The system is affected if the UPnP Device Host service is running, the Windows version is below the patched build numbers, and UPnP is enabled or exposed to an adjacent network attacker.
Generated from the published advisory. Verify against your own configuration.
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 · scoped10.0.10240.2107310.0.14393.824610.0.17763.7558
Apply the relevant Microsoft security update for this vulnerability (once released) and restrict network access to UPnP services through firewall rules or by disabling UPnP if not required.
Windows 10 1507: KB5057656 (10.0.10240.21073) | Windows 10 1607: KB5057653 (10.0.14393.8246) | Windows 10 1809: KB5053656 (10.0.17763.7558) | Windows 10 21h2: KB5055528 (10.0.19044.6093) | Windows 10 22h2: KB5055528 (10.0.19045.6093) | Windows 11 22h2: KB5055523 (10.0.22621.5624) | Windows 11 23h2:
- Open Windows Settings and navigate to Update & Security > Windows Update
- Click 'Check for updates' to download and install the latest cumulative security update
- Alternatively, manually download and install the specific KB patch for your Windows version from the Microsoft Update Catalog
- Restart the system after applying the update to ensure the UPnP Device Host vulnerability is remediated
- Verify the update was successfully installed by checking Windows Update history for the KB number corresponding to CVE-2025-48821
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-48821 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-48821 in production — separate from our analysis above.
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
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- Version or environment caveats, and links to real fixes
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