Microsoft .NET: Remote code execution via out-of-bounds write in WPF

Summary

An out-of-bounds write in the WPF runtime of Microsoft .NET 8 to 11 and in affected Visual Studio versions allows remote code execution. Crafted WPF pixel-shader bytecode can desynchronize the parsing passes in CPSTrans::Initialize, which leads to heap out-of-bounds writes or reads. An attacker needs no privileges, but a user must open or load the crafted content, for example from a phishing file or link, and the flaw affects only Windows desktop applications that render untrusted shaders.

Affected

• Microsoft .NET 8: 8.0.0 to 8.0.31
• Microsoft .NET 9: 9.0.0 to 9.0.20
• Microsoft .NET 10: 10.0.0 to 10.0.12
• Microsoft .NET 11 previews: 11.0.0-preview.1 to 11.0.0-rc.1
• Visual Studio 2022 version 17.14: 17.14.0 to 17.14.42 (before 17.14.42)
• Visual Studio 2026 version 18.10: 18.10.0 to 18.10.4 (before 18.10.4)
• .NET 6 is not listed by Microsoft; a third-party claim about .NET 6 is unverified.

Fixed in

• .NET 8.0.32
• .NET 9.0.21
• .NET 10.0.13
• .NET 11.0.0-rc.2
• Visual Studio 2022 17.14.42 and Visual Studio 2026 18.10.4 or later (per the CVE record)

Workaround

Unknown. No vendor-published workaround was found. Until patched, avoid opening or loading untrusted WPF content and pixel shaders.

Exploitation

• Microsoft: not publicly disclosed and not known to be exploited; exploitability assessed as "Exploitation Less Likely".
• CISA SSVC: automatable no, exploitation none.
• Not listed in the CISA KEV catalog.
• No public proof of concept found.

Our recommendation

• Update .NET 8, 9, 10 and 11 runtimes and affected Visual Studio installations to the fixed versions from the October 2026 servicing release.
• Rebuild and redeploy self-contained WPF applications, and update package references to patched versions.
• Identify WPF applications that load untrusted content or shaders, such as custom viewers and line-of-business tools, and restrict or avoid such content until patched.
• Treat unexpected files and links from untrusted sources with caution.

Public exploits iAttack code is publicly available (PoC on GitHub, Metasploit or Exploit-DB).

PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.

Research sources

• Microsoft Security Update Guide: CVE-2026-96235 msrc.microsoft.com
• dotnet announcements issue 483 (Microsoft advisory mirror) github.com
• GitHub Advisory GHSA-g44w-h65v-4cw9 github.com
• Ubuntu Security: CVE-2026-96235 ubuntu.com
• OpenCVE: CVE-2026-96235 app.opencve.io

Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 31 Oct 2026, 17:55.