---
id: CVE-2026-70197
title: >-
  Out-of-bounds write in .NET allows an unauthorized attacker to execute code
  over a network.
summary: >-
  Out-of-bounds write in .NET allows an unauthorized attacker to execute code
  over a network.
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-787
published: '2026-10-13'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T04:18:33.297'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-70197'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70197'
    label: secure@microsoft.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-70197.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-70197'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2551007'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-70197'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-70197'
  - url: 'https://github.com/dotnet/runtime/security/advisories/GHSA-4mpw-cpwj-hxxj'
  - url: 'https://github.com/dotnet/announcements/issues/466'
  - url: 'https://github.com/dotnet/runtime/issues/135702'
  - url: 'https://github.com/advisories/GHSA-4mpw-cpwj-hxxj'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
  - ghsa
  - nuget
ingestedAt: '2026-10-13T19:43:29.024Z'
vendor: Microsoft
product: .NET 10.0
affected:
  - .net_10.0 >= 10.0.0 < 10.0.13
  - .net_11.0 >= 11.0.0 < 11.0.0-rc.2
  - .net_8.0 >= 8.0.0 < 8.0.32
  - .net_9.0 >= 9.0.0 < 9.0.21
  - visual_studio_2022_version_17.14 >= 17.14.0 < 17.14.42
  - visual_studio_2026_version_18.10 >= 18.10.0 < 18.10.4
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-08T00:00:00+00:00'
epss: 0.00788
epssPercentile: 0.56006
aliases:
  - GHSA-4mpw-cpwj-hxxj
ecosystem: nuget
patched:
  - Microsoft.NETCore.App.Runtime.win-arm64 8.0.32
  - Microsoft.NETCore.App.Runtime.win-x64 8.0.32
  - Microsoft.NETCore.App.Runtime.win-x86 8.0.32
  - Microsoft.NETCore.App.Runtime.win-arm64 11.0.0-rc.2
  - Microsoft.NETCore.App.Runtime.win-x64 11.0.0-rc.2
  - Microsoft.NETCore.App.Runtime.win-x86 11.0.0-rc.2
  - Microsoft.NETCore.App.Runtime.win-arm64 9.0.21
  - Microsoft.NETCore.App.Runtime.win-x64 9.0.21
  - Microsoft.NETCore.App.Runtime.win-x86 9.0.21
  - Microsoft.NETCore.App.Runtime.win-arm64 10.0.13
  - Microsoft.NETCore.App.Runtime.win-x64 10.0.13
  - Microsoft.NETCore.App.Runtime.win-x86 10.0.13
---

## Overview

Out-of-bounds write 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.

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Hardened Images · no fix planned: Red Hat Hardened Images · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-70197.json)

## Package advisory (CVE-2026-70197)

Affected packages:

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

Patched in:

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

Source: https://github.com/advisories/GHSA-4mpw-cpwj-hxxj