# CVE-2026-62871: Out-of-bounds write in .NET allows an unauthorized attacker to execute code locally.

Source: https://junglewise.ai/threats/cve-2026-62871-microsoft-net-wpf-heap-overflow-and-elevation-of-privilege  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-11. Updated: 2026-08-11  
License: CC BY 4.0 with a link back

CVE-2026-62871 · Severity: high · CVSS 7.8 · Published 2026-08-11

A security vulnerability has been identified in Windows Presentation Foundation (WPF), a framework used for building Windows desktop applications. An attacker could exploit this flaw to gain higher privileges or execute unauthorized code on a user's computer if the user interacts with a malicious file or application. This could lead to a full system compromise, data theft, or operational disruption.

Technologies: [Apple macOS](https://junglewise.ai/threats/technologies/macos), [Linux Kernel](https://junglewise.ai/threats/technologies/kernel), [Microsoft .Net](https://junglewise.ai/threats/technologies/microsoft-net), [Microsoft Visual Studio 2022](https://junglewise.ai/threats/technologies/visual-studio-2022), [Microsoft Visual Studio 2026](https://junglewise.ai/threats/technologies/visual-studio), [Microsoft Windows](https://junglewise.ai/threats/technologies/windows), [Microsoft.WindowsDesktop.App.Runtime.win-arm64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-windowsdesktop-app-runtime-win-arm64), [Microsoft.WindowsDesktop.App.Runtime.win-x64 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-windowsdesktop-app-runtime-win-x64), [Microsoft.WindowsDesktop.App.Runtime.win-x86 (NuGet)](https://junglewise.ai/threats/technologies/microsoft-windowsdesktop-app-runtime-win-x86). Vendors: [Apple](https://junglewise.ai/threats/vendors/apple), [Linux](https://junglewise.ai/threats/vendors/linux), [Microsoft](https://junglewise.ai/threats/vendors/microsoft), [NuGet](https://junglewise.ai/threats/vendors/nuget).

## Quick answers

**Is CVE-2026-62871 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-62871 being exploited in the wild.

**How severe is CVE-2026-62871?** High severity, with a CVSS score of 7.8, published 11 August 2026.

**Which products and versions are affected?** Microsoft Windows Desktop Runtime 8.0.0 - 8.0.29, 9.0.0 - 9.0.18, 10.0.0 - 10.0.10; 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-2026-62871?** 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-2026-62871 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-62871?** Check whether you run Apple macOS, Linux Kernel, Microsoft .Net 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

  ```sh
  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

  ```sh
  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

  ```sh
  dotnet add package Microsoft.WindowsDesktop.App.Runtime.win-x86 --version 10.0.11
  ```


## Technical details

A heap-based buffer overflow (CWE-122) and out-of-bounds write (CWE-787) vulnerability exists in Windows Presentation Foundation (WPF) within the .NET runtime. The flaw is triggered when the application writes data past the end of an intended heap-allocated buffer. An attacker can exploit this locally by convincing a user to open a specially crafted file or run a malicious application, leading to arbitrary code execution with the privileges of the current user. The vulnerability affects .NET 8, 9, and 10 on Windows platforms. Patches are available in .NET versions 8.0.30, 9.0.19, and 10.0.11.

## Affected products

- Microsoft Microsoft.WindowsDesktop.App.Runtime.win-arm64 8.0.0 - 8.0.29, 9.0.0 - 9.0.18, 10.0.0 - 10.0.10
- Microsoft Microsoft.WindowsDesktop.App.Runtime.win-x64 8.0.0 - 8.0.29, 9.0.0 - 9.0.18, 10.0.0 - 10.0.10
- Microsoft Microsoft.WindowsDesktop.App.Runtime.win-x86 8.0.0 - 8.0.29, 9.0.0 - 9.0.18, 10.0.0 - 10.0.10

## Identifiers

- CVE-2026-62871
- GHSA-vg44-h755-9hw7

## Timeline

- 2026-08-11: advisory
- 2026-08-11: patched

## References

- [https://github.com/dotnet/wpf/security/advisories/GHSA-vg44-h755-9hw7](https://github.com/dotnet/wpf/security/advisories/GHSA-vg44-h755-9hw7)
- [https://github.com/dotnet/announcements/issues/431](https://github.com/dotnet/announcements/issues/431)
- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62871](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62871)
- [https://api.github.com/repos/dotnet/wpf/security-advisories/GHSA-vg44-h755-9hw7](https://api.github.com/repos/dotnet/wpf/security-advisories/GHSA-vg44-h755-9hw7)

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