CVE-2026-50646: Microsoft .NET Framework protection mechanism failure

CVE-2026-50646 · Severity: high · CVSS 7.8 · Published 2026-07-14

Windows Presentation Foundation (WPF), a framework used to build Windows desktop applications, contains a vulnerability that allows attackers to execute arbitrary code when an application processes specially crafted XAML files. An attacker could trick a user into opening a malicious XAML file or manipulate application data to trigger the vulnerability, resulting in complete system compromise under the current user's privileges.

Technologies: Microsoft .NET Framework, Microsoft Windows Presentation Foundation, Microsoft WindowsDesktop.App.Runtime.win-arm64, Microsoft WindowsDesktop.App.Runtime.win-x64, Microsoft WindowsDesktop.App.Runtime.win-x86, 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-2026-50646 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-50646 being exploited in the wild.
How severe is CVE-2026-50646?
High severity, with a CVSS score of 7.8, published 14 July 2026.
Which products and versions are affected?
Microsoft .NET Framework 3.5.0 to 2.0.50727.8983 & 3.0.30729.8978; Microsoft Windows Presentation Foundation .NET 8.0.0–8.0.28, .NET 9.0.0–9.0.17, .NET 10.0.0–10.0.9; Microsoft WindowsDesktop.App.Runtime.win-arm64 8.0.0–8.0.28, 9.0.0–9.0.17, 10.0.0–10.0.9; Microsoft WindowsDesktop.App.Runtime.win-x64 8.0.0–8.0.28, 9.0.0–9.0.17, 10.0.0–10.0.9; and 4 more.
Is there a fix for CVE-2026-50646?
Yes. Microsoft.WindowsDesktop.App.Runtime.win-arm64 (NuGet): upgrade to 10.0.10 or later; Microsoft.WindowsDesktop.App.Runtime.win-x64 (NuGet): upgrade to 10.0.10 or later; Microsoft.WindowsDesktop.App.Runtime.win-x86 (NuGet): upgrade to 10.0.10 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-50646 attacked?
It is attacked with local access, in a software library.
Am I affected by CVE-2026-50646?
Check whether you run Microsoft .NET Framework, Microsoft Windows Presentation Foundation, Microsoft WindowsDesktop.App.Runtime.win-arm64 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 10.0.10 or later
    dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-arm64 --version 10.0.10
  • Microsoft.WindowsDesktop.App.Runtime.win-x64 (NuGet): upgrade to 10.0.10 or later
    dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-x64 --version 10.0.10
  • Microsoft.WindowsDesktop.App.Runtime.win-x86 (NuGet): upgrade to 10.0.10 or later
    dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-x86 --version 10.0.10

Technical details

The vulnerability is a protection mechanism failure (CWE-693) in WPF's XAML parser that fails to properly sanitize or validate untrusted XAML markup before processing. The attack vector is local with user interaction required—an attacker must provide specially crafted XAML input that a WPF application processes. Affected versions include .NET 8.0.0 through 8.0.28, .NET 9.0.0 through 9.0.17, and .NET 10.0.0 through 10.0.9. Successful exploitation allows arbitrary code execution with the privileges of the user running the application. Patches are available via updated NuGet packages (Microsoft.WindowsDesktop.App.Runtime) targeting the patched versions 8.0.29, 9.0.18, and 10.0.10. Applications using self-contained deployments must be recompiled and redeployed.

Affected products

  • Microsoft Windows Presentation Foundation (WPF) .NET 8.0.0–8.0.28, .NET 9.0.0–9.0.17, .NET 10.0.0–10.0.9
  • Microsoft Microsoft.WindowsDesktop.App.Runtime.win-arm64 8.0.0–8.0.28, 9.0.0–9.0.17, 10.0.0–10.0.9
  • Microsoft Microsoft.WindowsDesktop.App.Runtime.win-x64 8.0.0–8.0.28, 9.0.0–9.0.17, 10.0.0–10.0.9
  • Microsoft Microsoft.WindowsDesktop.App.Runtime.win-x86 8.0.0–8.0.28, 9.0.0–9.0.17, 10.0.0–10.0.9

Identifiers

  • CVE-2026-50646
  • GHSA-gh2h-rhph-h37g

Timeline

  • 2026-07-14: disclosed: Advisory published
  • 2026-07-14: patched: Patches available: .NET 8.0.29, 9.0.18, 10.0.10

References

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