CVE-2026-26172
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 · uneditedConcurrent execution using shared resource with improper synchronization ('race condition') in Windows Push Notifications 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 confidenceThis is a race condition vulnerability in Windows Push Notifications where concurrent access to shared resources lacks proper synchronization. An authorized local attacker can exploit this timing vulnerability to escalate privileges to higher permission levels, potentially achieving administrator or system-level access.
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< 10.0.19044.7184< 10.0.19045.7184< 10.0.22631.6936< 10.0.26100.8246< 10.0.26200.8246< 10.0.28000.1836< 10.0.20348.5020< 10.0.25398.2274CVSS 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
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/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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Identify Windows version and build numberRun 'winver' from Run dialog or execute 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' in Command Prompt. Alternatively, run 'ver' command to get build number, or check 'winmsdp.exe' output for detailed build info.Affected if The build number falls below the fixed version numbers for your Windows release (e.g., 19044.x for Win10 21h2, 19045.x for Win10 22h2, 22631.x for Win11 23h2, etc.)
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Locate Windows Push Notifications serviceOpen Services console (services.msc) and locate 'Windows Push Notifications User Service' (WpnUserService) or check via PowerShell: 'Get-Service WpnUserService' or 'Get-Service WpnService'Affected if The Windows Push Notifications service exists and is running on the system. The vulnerability requires this service to be accessible for exploitation.
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Verify service status and startup typeIn Services console, check the service status (Running/Stopped) and Startup Type. Also check via PowerShell: 'Get-Service WpnUserService | Select-Object Name,Status,StartType'Affected if The service is running (Status equals 'Running') and can be accessed by local authenticated users. A stopped service reduces the attack surface but the vulnerability may still apply if the service can be started.
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Check for untrusted or low-privilege local usersReview local user accounts via 'net user' and check user group memberships via 'net localgroup' to identify non-administrator accounts that have local logon rights.Affected if There are standard user accounts, guest accounts, or other low-privilege users present on the system who could potentially exploit this privilege escalation vulnerability.
Your system is affected if it runs a Windows version within the affected build ranges AND has the Windows Push Notifications service running with accessible user accounts that could trigger the race condition.
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 · scoped10.0.19044.718410.0.19045.718410.0.20348.5020
Apply Microsoft security updates for Windows once released. Prioritize patching systems with user-facing roles and those where untrusted users have local access. Verify the Windows Push Notifications service is running with least-privilege accounts.
Windows 10 21h2: build 10.0.19044.7184 or later | Windows 10 22h2: build 10.0.19045.7184 or later | Windows 11 23h2: build 10.0.22631.6936 or later | Windows 11 24h2: build 10.0.26100.8246 or later | Windows 11 25h2: build 10.0.26200.8246 or later | Windows 11 26h1: build 10.0.28000.1836 or later |
- Identify the current Windows version by running 'winver' or 'systeminfo' in Command Prompt
- Determine which build version you're currently running (e.g., 10.0.19044.x for Windows 10 21h2)
- For Windows 10 21h2 (build 19044): Upgrade to build 10.0.19044.7184 or later via Windows Update or download the corresponding cumulative update
- For Windows 10 22h2 (build 19045): Upgrade to build 10.0.19045.7184 or later via Windows Update or download the corresponding cumulative update
- For Windows 11 23h2 (build 22631): Upgrade to build 10.0.22631.6936 or later via Windows Update or download the corresponding cumulative update
- For Windows 11 24h2 (build 26100): Upgrade to build 10.0.26100.8246 or later via Windows Update or download the corresponding cumulative update
- For Windows 11 25h2 (build 26200): Upgrade to build 10.0.26200.8246 or later via Windows Update or download the corresponding cumulative update
- For Windows 11 26h1 (build 28000): Upgrade to build 10.0.28000.1836 or later via Windows Update or download the corresponding cumulative update
Generated from the published advisory — verify against the referenced sources before acting.
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- 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-2026-26172 — 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-2026-26172 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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- 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