CVE-2026-70354: Out-of-bounds write in .NET allows an unauthorized attacker to execute code locally.

CVE-2026-70354 · Severity: high · CVSS 7.8 · Published 2026-08-11

A security vulnerability exists in Windows Presentation Foundation (WPF), a framework used for building Windows desktop applications. An attacker could exploit this flaw to run unauthorized code on a user's computer, potentially leading to a full system compromise or data theft. This typically requires a user to perform a specific action, such as opening a malicious file or application.

Technologies: Microsoft .Net, Microsoft .NET Framework, Microsoft Visual Studio 2022, Microsoft Visual Studio 2026, Microsoft Windows, Microsoft Windows Presentation Foundation, Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2, Microsoft Windows 11 26h1, Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019, Microsoft Windows Server 2022, Microsoft Windows Server 2025, 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-2026-70354 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-70354 being exploited in the wild.
How severe is CVE-2026-70354?
High severity, with a CVSS score of 7.8, published 11 August 2026.
Which products and versions are affected?
Microsoft Windows Presentation Foundation All versions using affected .NET runtimes; Microsoft.WindowsDesktop.App.Runtime.win-arm64 (NuGet) ECOSYSTEM:introduced=10.0.0,fixed=10.0.11; Microsoft.WindowsDesktop.App.Runtime.win-x64 (NuGet) ECOSYSTEM:introduced=10.0.0,fixed=10.0.11; Microsoft.WindowsDesktop.App.Runtime.win-x86 (NuGet) ECOSYSTEM:introduced=10.0.0,fixed=10.0.11.
Is there a fix for CVE-2026-70354?
Yes. Microsoft.WindowsDesktop.App.Runtime.win-arm64 (NuGet): upgrade to 10.0.11 or later; Microsoft.WindowsDesktop.App.Runtime.win-x64 (NuGet): upgrade to 10.0.11 or later; Microsoft.WindowsDesktop.App.Runtime.win-x86 (NuGet): upgrade to 10.0.11 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-70354 attacked?
It is attacked with local access, in a software library.
Am I affected by CVE-2026-70354?
Check whether you run Microsoft .Net, Microsoft .NET Framework, Microsoft Visual Studio 2022 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 10.0.11 or later
    dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-arm64 --version 10.0.11
  • Microsoft.WindowsDesktop.App.Runtime.win-x64 (NuGet): upgrade to 10.0.11 or later
    dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-x64 --version 10.0.11
  • Microsoft.WindowsDesktop.App.Runtime.win-x86 (NuGet): upgrade to 10.0.11 or later
    dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-x86 --version 10.0.11

Technical details

An out-of-bounds write vulnerability (CWE-787) exists in the Windows Presentation Foundation (WPF) component of .NET. The flaw is triggered when the application writes data outside the boundaries of the intended buffer, which can be leveraged by an attacker to achieve arbitrary code execution. Exploitation requires local access and user interaction, such as a user running a specially crafted application. The vulnerability affects .NET 8, 9, and 10 runtimes on Windows. Microsoft has released patches (versions 8.0.30, 9.0.19, and 10.0.11) to address this issue.

Affected products

  • Microsoft .NET 10 >= 10.0.0, <= 10.0.10
  • Microsoft .NET 9 >= 9.0.0, <= 9.0.18
  • Microsoft .NET 8 >= 8.0.0, <= 8.0.29
  • Microsoft Windows Presentation Foundation All versions using affected .NET runtimes

Identifiers

  • CVE-2026-70354
  • GHSA-gg8c-3338-xw2f

Timeline

  • 2026-08-11: disclosed
  • 2026-08-11: advisory
  • 2026-08-11: patched

References

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