CVE-2026-70007: Microsoft .NET and Visual Studio WPF heap out-of-bounds write

CVE-2026-70007 · Severity: high · CVSS 8.8 · Published 2026-10-13

Windows Presentation Foundation (WPF), a framework for building desktop applications on Windows, contains a critical flaw in pixel-shader bytecode parsing that can be triggered by opening a specially crafted document. An attacker can exploit this to read or write memory outside intended boundaries, potentially gaining full control of an affected system.

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-2026-70007 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-70007 being exploited in the wild.
How severe is CVE-2026-70007?
High severity, with a CVSS score of 8.8, published 13 October 2026.
Which products and versions are affected?
Microsoft .Net 8.0.0–8.0.31, 9.0.0–9.0.20, 10.0.0–10.0.12, 11.0.0-preview.1–11.0.0-rc.1; Microsoft Visual Studio versions using affected .NET runtimes; 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-2026-70007?
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-2026-70007 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-70007?
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

Malformed WPF pixel-shader bytecode causes desynchronization between two parsing passes in CPSTrans::Initialize, leading to out-of-bounds heap writes or reads. The vulnerability requires user interaction (opening a crafted file) and network access is the attack vector. Successful exploitation allows arbitrary code execution with the privileges of the user running the application.

Affected products

  • Microsoft .NET 8.0.0–8.0.31, 9.0.0–9.0.20, 10.0.0–10.0.12, 11.0.0-preview.1–11.0.0-rc.1
  • Microsoft Visual Studio versions using affected .NET runtimes

Identifiers

  • CVE-2026-70007
  • GHSA-pfwj-2f93-rf42

Timeline

  • 2026-10-13: disclosed

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.