---
id: CVE-2026-87697
title: >-
  Deserialization of untrusted data in .NET allows an unauthorized attacker to
  execute code over a network.
summary: >-
  Deserialization of untrusted data in .NET allows an unauthorized attacker to
  execute code over a network.
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
cwe:
  - CWE-502
vendor: Microsoft
product: Microsoft.WindowsDesktop.App.Runtime.win-arm64
affected:
  - 'Microsoft.WindowsDesktop.App.Runtime.win-arm64 >= 9.0.0, <= 9.0.20'
  - 'Microsoft.WindowsDesktop.App.Runtime.win-x64 >= 9.0.0, <= 9.0.20'
  - 'Microsoft.WindowsDesktop.App.Runtime.win-x86 >= 9.0.0, <= 9.0.20'
  - 'Microsoft.WindowsDesktop.App.Runtime.win-arm64 >= 8.0.0, <= 8.0.31'
  - 'Microsoft.WindowsDesktop.App.Runtime.win-x64 >= 8.0.0, <= 8.0.31'
  - 'Microsoft.WindowsDesktop.App.Runtime.win-x86 >= 8.0.0, <= 8.0.31'
  - >-
    Microsoft.WindowsDesktop.App.Runtime.win-arm64 >= 11.0.0-preview.1, <=
    11.0.0-rc.1
  - >-
    Microsoft.WindowsDesktop.App.Runtime.win-x64 >= 11.0.0-preview.1, <=
    11.0.0-rc.1
  - >-
    Microsoft.WindowsDesktop.App.Runtime.win-x86 >= 11.0.0-preview.1, <=
    11.0.0-rc.1
  - 'Microsoft.WindowsDesktop.App.Runtime.win-arm64 >= 10.0.0, <= 10.0.12'
  - 'Microsoft.WindowsDesktop.App.Runtime.win-x64 >= 10.0.0, <= 10.0.12'
  - 'Microsoft.WindowsDesktop.App.Runtime.win-x86 >= 10.0.0, <= 10.0.12'
patched:
  - Microsoft.WindowsDesktop.App.Runtime.win-arm64 9.0.21
  - Microsoft.WindowsDesktop.App.Runtime.win-x64 9.0.21
  - Microsoft.WindowsDesktop.App.Runtime.win-x86 9.0.21
  - Microsoft.WindowsDesktop.App.Runtime.win-arm64 8.0.32
  - Microsoft.WindowsDesktop.App.Runtime.win-x64 8.0.32
  - Microsoft.WindowsDesktop.App.Runtime.win-x86 8.0.32
  - Microsoft.WindowsDesktop.App.Runtime.win-arm64 11.0.0-rc.2
  - Microsoft.WindowsDesktop.App.Runtime.win-x64 11.0.0-rc.2
  - Microsoft.WindowsDesktop.App.Runtime.win-x86 11.0.0-rc.2
  - Microsoft.WindowsDesktop.App.Runtime.win-arm64 10.0.13
  - Microsoft.WindowsDesktop.App.Runtime.win-x64 10.0.13
  - Microsoft.WindowsDesktop.App.Runtime.win-x86 10.0.13
published: '2026-10-13'
updated: '2026-10-13'
sourceUpdated: '2026-10-13T21:19:37.640'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-87697'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-87697'
    label: secure@microsoft.com
  - url: 'https://github.com/dotnet/wpf/security/advisories/GHSA-c27m-942f-rcfh'
  - url: 'https://github.com/dotnet/announcements/issues/471'
  - url: 'https://github.com/dotnet/wpf/issues/12021'
  - url: 'https://github.com/advisories/GHSA-c27m-942f-rcfh'
tags:
  - nvd
  - ghsa
  - nuget
aliases:
  - GHSA-c27m-942f-rcfh
ecosystem: nuget
ingestedAt: '2026-10-13T19:43:29.201Z'
---

## Overview

Deserialization of untrusted data in .NET allows an unauthorized attacker to execute code over a network.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-87697)

Affected packages:

- `Microsoft.WindowsDesktop.App.Runtime.win-arm64 >= 9.0.0, <= 9.0.20`
- `Microsoft.WindowsDesktop.App.Runtime.win-x64 >= 9.0.0, <= 9.0.20`
- `Microsoft.WindowsDesktop.App.Runtime.win-x86 >= 9.0.0, <= 9.0.20`
- `Microsoft.WindowsDesktop.App.Runtime.win-arm64 >= 8.0.0, <= 8.0.31`
- `Microsoft.WindowsDesktop.App.Runtime.win-x64 >= 8.0.0, <= 8.0.31`
- `Microsoft.WindowsDesktop.App.Runtime.win-x86 >= 8.0.0, <= 8.0.31`
- `Microsoft.WindowsDesktop.App.Runtime.win-arm64 >= 11.0.0-preview.1, <= 11.0.0-rc.1`
- `Microsoft.WindowsDesktop.App.Runtime.win-x64 >= 11.0.0-preview.1, <= 11.0.0-rc.1`
- `Microsoft.WindowsDesktop.App.Runtime.win-x86 >= 11.0.0-preview.1, <= 11.0.0-rc.1`
- `Microsoft.WindowsDesktop.App.Runtime.win-arm64 >= 10.0.0, <= 10.0.12`
- `Microsoft.WindowsDesktop.App.Runtime.win-x64 >= 10.0.0, <= 10.0.12`
- `Microsoft.WindowsDesktop.App.Runtime.win-x86 >= 10.0.0, <= 10.0.12`

Patched in:

- `Microsoft.WindowsDesktop.App.Runtime.win-arm64 9.0.21`
- `Microsoft.WindowsDesktop.App.Runtime.win-x64 9.0.21`
- `Microsoft.WindowsDesktop.App.Runtime.win-x86 9.0.21`
- `Microsoft.WindowsDesktop.App.Runtime.win-arm64 8.0.32`
- `Microsoft.WindowsDesktop.App.Runtime.win-x64 8.0.32`
- `Microsoft.WindowsDesktop.App.Runtime.win-x86 8.0.32`
- `Microsoft.WindowsDesktop.App.Runtime.win-arm64 11.0.0-rc.2`
- `Microsoft.WindowsDesktop.App.Runtime.win-x64 11.0.0-rc.2`
- `Microsoft.WindowsDesktop.App.Runtime.win-x86 11.0.0-rc.2`
- `Microsoft.WindowsDesktop.App.Runtime.win-arm64 10.0.13`
- `Microsoft.WindowsDesktop.App.Runtime.win-x64 10.0.13`
- `Microsoft.WindowsDesktop.App.Runtime.win-x86 10.0.13`

Source: https://github.com/advisories/GHSA-c27m-942f-rcfh