CVE-2026-23656
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 · uneditedInsufficient verification of data authenticity in Windows App Installer allows an unauthorized attacker to perform spoofing 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 confidenceThis is a spoofing vulnerability in Windows App Installer stemming from insufficient verification of data authenticity. An unauthenticated attacker positioned on the network could potentially impersonate legitimate App Installer content or services to deliver malicious packages.
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< 2.0.964.0CVSS 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
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
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 Windows App Installer versionOpen PowerShell and run: Get-AppxPackage -Name Microsoft.DesktopAppInstaller | Select-Object Name, VersionAffected if The installed version is less than 2.0.964.0 or the package is not found (indicating it may not be installed or has been removed)
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Confirm App Installer package existsRun: Get-AppxPackage *AppInstaller* in PowerShell to verify the package is installed on the systemAffected if The package Microsoft.DesktopAppInstaller is present with a vulnerable version number below 2.0.964.0
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Check App Installer configuration settingsReview App Installer related settings in Settings > Apps > Apps & features > App Installer options, or check registry under HKLM:\SOFTWARE\Policies\Microsoft\AppInstaller for any override configurationsAffected if Settings allow installation from sources other than the Microsoft Store or trusted paths without additional verification
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Verify network-exposed App Installer usageCheck if App Installer is configured to use network-based installation sources or enterprise deployment features by reviewing: Get-AppxPackage -AllUsers Microsoft.DesktopAppInstaller | Get-AppxPackagePropertiesAffected if Installation sources include HTTP/HTTPS network paths or UNC paths that could be intercepted by an attacker on the network
You are affected if Windows App Installer is installed and its version is below 2.0.964.0, and the system uses it to install packages from network or non-store sources without additional integrity verification.
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 · scoped2.0.964.0
Apply Microsoft security updates for Windows App Installer when available; until then, enforce installation of apps only from trusted sources and verify package integrity through official channels.
2.0.964.0
- Open Settings on your Windows device
- Navigate to Windows Update
- Check for updates and install any available updates for Windows App Installer
- Alternatively, open Microsoft Store and check for updates to the App Installer package
- Verify the updated version is 2.0.964.0 or later by running 'Get-AppxPackage *AppInstaller*' in PowerShell
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-23656 — 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-2026-23656 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