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HIGH severity

GHSA-gh2h-rhph-h37g

HIGH

GHSA-gh2h-rhph-h37g is a high-severity (CVSS 7.8) Deserialization of Untrusted Data vulnerability in Microsoft.WindowsDesktop.App.Runtime.win-x64. O3 Security confirms whether GHSA-gh2h-rhph-h37g is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Microsoft Security Advisory CVE-2026-50646 – .NET Remote Code Execution Vulnerability

Also known asBIT-dotnet-2026-50646BIT-dotnet-sdk-2026-50646CVE-2026-50646
Published
Sep 8, 2026
Updated
Sep 8, 2026
Affected
9 pkgs
Patched
9 / 9
Exploits
None indexed
Exploitation data as of Sep 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

9 pkgs affected
.NETMicrosoft.WindowsDesktop.App.Runtime.win-x64.NETMicrosoft.WindowsDesktop.App.Runtime.win-x86.NETMicrosoft.WindowsDesktop.App.Runtime.win-arm64.NETMicrosoft.WindowsDesktop.App.Runtime.win-x64.NETMicrosoft.WindowsDesktop.App.Runtime.win-x86.NETMicrosoft.WindowsDesktop.App.Runtime.win-arm64.NETMicrosoft.WindowsDesktop.App.Runtime.win-x64.NETMicrosoft.WindowsDesktop.App.Runtime.win-x86+1 more

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.

Description

Executive summary

Microsoft is releasing this security advisory to provide information about a vulnerability in Windows Presentation Foundation (WPF). This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

A remote code execution vulnerability exists in Windows Presentation Foundation (WPF) in .NET 8, .NET 9, and .NET 10 when parsing specially crafted XAML input. An attacker who successfully exploits this vulnerability could execute arbitrary code in the context of the current user.

Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/**TBD**

CVSS Details

  • Version: 3.1
  • Severity: High
  • Score: 7.8
  • Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
  • Weakness: CWE-693 (Protection Mechanism Failure)

Affected Platforms

  • Platforms: Windows
  • Architectures: All

<a name="affected-packages"></a>Affected Packages

The vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below

<a name=".NET 10.0"></a>.NET 10.0

Package nameAffected versionPatched version
Microsoft.WindowsDesktop.App.Runtime.win-arm64>= 10.0.0, <= 10.0.910.0.10
Microsoft.WindowsDesktop.App.Runtime.win-x64>= 10.0.0, <= 10.0.910.0.10
Microsoft.WindowsDesktop.App.Runtime.win-x86>= 10.0.0, <= 10.0.910.0.10

<a name=".NET 9.0"></a>.NET 9.0

Package nameAffected versionPatched version
Microsoft.WindowsDesktop.App.Runtime.win-arm64>= 9.0.0, <= 9.0.179.0.18
Microsoft.WindowsDesktop.App.Runtime.win-x64>= 9.0.0, <= 9.0.179.0.18
Microsoft.WindowsDesktop.App.Runtime.win-x86>= 9.0.0, <= 9.0.179.0.18

<a name=".NET 8.0"></a>.NET 8.0

Package nameAffected versionPatched version
Microsoft.WindowsDesktop.App.Runtime.win-arm64>= 8.0.0, <= 8.0.288.0.29
Microsoft.WindowsDesktop.App.Runtime.win-x64>= 8.0.0, <= 8.0.288.0.29
Microsoft.WindowsDesktop.App.Runtime.win-x86>= 8.0.0, <= 8.0.288.0.29

Advisory FAQ

<a name="how-affected"></a>How do I know if I am affected?

If using a package listed in affected packages, developers exposed to the vulnerability.

<a name="how-fix"></a>How do I fix the issue?

  1. To fix the issue please install the latest version of .NET. If developers have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt them to update Visual Studio, which will also update their .NET SDKs.
  2. If their application references the vulnerable nuget package, update the package reference to the patched version. Developers can list the versions they have installed by running the dotnet --info command.

Once developers have installed the updated runtime or SDK, they should restart their apps for the update to take effect.

Additionally, if they've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed.

Other Information

Reporting Security Issues

If anyone has found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ.

Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty.

Support

Direct questions about this issue to GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. Users can ask questions in the linked discussion issue.

Disclaimer

The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

External Links

CVE-2026-50646

Acknowledgements

Kevin Gosse, 41ae55e9310ff27fa6f26af4727e5590, Ky0toFu

Revisions

V1.0 (July 14, 2026): Advisory published.

Affected Packages

9 total 9 fixed
EcosystemPackageVulnerable rangeFix
.NETNuGetMicrosoft.WindowsDesktop.App.Runtime.win-x6410.0.0&&< 10.0.1010.0.10
.NETNuGetMicrosoft.WindowsDesktop.App.Runtime.win-x8610.0.0&&< 10.0.1010.0.10
.NETNuGetMicrosoft.WindowsDesktop.App.Runtime.win-arm6410.0.0&&< 10.0.1010.0.10
.NETNuGetMicrosoft.WindowsDesktop.App.Runtime.win-x649.0.0&&< 9.0.189.0.18
.NETNuGetMicrosoft.WindowsDesktop.App.Runtime.win-x869.0.0&&< 9.0.189.0.18
.NETNuGetMicrosoft.WindowsDesktop.App.Runtime.win-arm649.0.0&&< 9.0.189.0.18

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.WindowsDesktop.App.Runtime.win-x64. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update Microsoft.WindowsDesktop.App.Runtime.win-x64 to 10.0.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-gh2h-rhph-h37g is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether GHSA-gh2h-rhph-h37g is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-gh2h-rhph-h37g. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

## Executive summary Microsoft is releasing this security advisory to provide information about a vulnerability in Windows Presentation Foundation (WPF). This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A remote code execution vulnerability exists in Windows Presentation Foundation (WPF) in .NET 8, .NET 9, and .NET 10 when parsing specially crafted XAML input. An attacker who successfully exploits this vulnerability could execute arbitrary code in the context of the current user. ## Announcement Announcement for this
O3 Security · Impact-Aware SCA

Is GHSA-gh2h-rhph-h37g in your dependencies?

O3 detects GHSA-gh2h-rhph-h37g across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

GHSA-gh2h-rhph-h37g: Microsoft.WindowsDe… | O3 Security