CVE-2026-96234: Microsoft .NET WPF origin validation error in URI handling

CVE-2026-96234 · Severity: medium · CVSS 5.3 · Published 2026-10-13

Microsoft .NET's Windows Presentation Foundation (WPF), a framework for building desktop applications on Windows, contains an information disclosure vulnerability in how it validates the origin of URIs during hyperlink navigation and resource loading. An attacker could craft a malicious XAML or XPS document that, when opened by a user, exposes sensitive information from the local system or bypasses intended security restrictions.

Technologies: Microsoft .Net, Microsoft Visual Studio, Microsoft.WindowsDesktop.App.Runtime.win-arm64 (NuGet), Microsoft.WindowsDesktop.App.Runtime.win-x64 (NuGet), Microsoft.WindowsDesktop.App.Runtime.win-x86 (NuGet). Vendors: Microsoft, NuGet.

Quick answers

Is CVE-2026-96234 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-96234 being exploited in the wild.
How severe is CVE-2026-96234?
Medium severity, with a CVSS score of 5.3, published 13 October 2026.
Which products and versions are affected?
Microsoft .Net 8.0.0 through 8.0.31, 9.0.0 through 9.0.20, 10.0.0 through 10.0.12, 11.0.0-preview.1 through 11.0.0-rc.1; Microsoft Visual Studio versions that bundle affected .NET SDKs; Microsoft.WindowsDesktop.App.Runtime.win-arm64 (NuGet) >= 9.0.0, <= 9.0.20, ECOSYSTEM:introduced=9.0.0,fixed=9.0.21; Microsoft.WindowsDesktop.App.Runtime.win-x64 (NuGet) >= 9.0.0, <= 9.0.20, ECOSYSTEM:introduced=9.0.0,fixed=9.0.21; and 1 more.
Is there a fix for CVE-2026-96234?
Yes. Microsoft.WindowsDesktop.App.Runtime.win-arm64 (NuGet): upgrade to 9.0.21 or later; Microsoft.WindowsDesktop.App.Runtime.win-x64 (NuGet): upgrade to 9.0.21 or later; Microsoft.WindowsDesktop.App.Runtime.win-x86 (NuGet): upgrade to 9.0.21 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-96234 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-96234?
Check whether you run Microsoft .Net, Microsoft Visual Studio, Microsoft.WindowsDesktop.App.Runtime.win-arm64 (NuGet) or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • Microsoft.WindowsDesktop.App.Runtime.win-arm64 (NuGet): upgrade to 9.0.21 or later
    dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-arm64 --version 9.0.21
  • Microsoft.WindowsDesktop.App.Runtime.win-x64 (NuGet): upgrade to 9.0.21 or later
    dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-x64 --version 9.0.21
  • Microsoft.WindowsDesktop.App.Runtime.win-x86 (NuGet): upgrade to 9.0.21 or later
    dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-x86 --version 9.0.21

Technical details

A CWE-346 origin validation error in Microsoft.WindowsDesktop.App.Runtime (WPF) allows unsafe URI fetching and navigation due to improper validation of resource origins. The vulnerability requires network access and user interaction (opening a malicious XAML/XPS document), and can result in information disclosure. Fixes include restrictive XAML and XPS security policies, TrueType font protection, XAML nesting-depth limits, and disabled caching of DNS zone-policy decisions.

Affected products

  • Microsoft .NET 8.0.0 through 8.0.31, 9.0.0 through 9.0.20, 10.0.0 through 10.0.12, 11.0.0-preview.1 through 11.0.0-rc.1
  • Microsoft Visual Studio versions that bundle affected .NET SDKs

Identifiers

  • CVE-2026-96234
  • GHSA-fq6x-pvr9-888r

Timeline

  • 2026-10-13: disclosed

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