---
id: CVE-2026-45491
title: .NET Tampering Vulnerability
summary: >-
  Improper link resolution before file access ('link following') in .NET allows
  an unauthorized attacker to perform tampering locally.
severity: medium
cvss: 6.2
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C'
cvssSource: cna
cwe:
  - CWE-59
vendor: Microsoft
product: .NET 10.0
affected:
  - .net_10.0 >= 10.0.0 < 10.0.9
  - .net_8.0 >= 8.0 < 8.0.28
  - .net_8.0 >= 8.0.0 < 8.0.28
  - .net_9.0 >= 9.0.0 < 9.0.17
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-06-10T12:17:16.966103Z'
published: '2026-06-09'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T13:43:46.222Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-45491'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45491'
    label: .NET Tampering Vulnerability
  - url: 'https://github.com/dotnet/runtime/security/advisories/GHSA-7q4v-2mr6-5gpx'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-45491'
  - url: 'https://github.com/dotnet/announcements/issues/404'
  - url: 'https://github.com/advisories/GHSA-7q4v-2mr6-5gpx'
tags:
  - cve.org
  - ghsa
  - nuget
epss: 0.00372
epssPercentile: 0.28386
aliases:
  - GHSA-7q4v-2mr6-5gpx
ecosystem: nuget
patched:
  - Microsoft.NETCore.App.Runtime.linux-x64 8.0.28
  - Microsoft.NETCore.App.Runtime.linux-x64 9.0.17
  - Microsoft.NETCore.App.Runtime.linux-x64 10.0.9
  - Microsoft.NETCore.App.Runtime.win-x64 8.0.28
  - Microsoft.NETCore.App.Runtime.win-x64 9.0.17
  - Microsoft.NETCore.App.Runtime.win-x64 10.0.9
  - Microsoft.NETCore.App.Runtime.osx-arm64 8.0.28
  - Microsoft.NETCore.App.Runtime.osx-arm64 9.0.17
  - Microsoft.NETCore.App.Runtime.osx-arm64 10.0.9
scores:
  cna: 6.2
  ghsa: 6.8
ingestedAt: '2026-07-07T15:41:58.347Z'
---

## Overview

Improper link resolution before file access ('link following') in .NET allows an unauthorized attacker to perform tampering locally.

## Affected

- `.net_10.0 >= 10.0.0 < 10.0.9`
- `.net_8.0 >= 8.0 < 8.0.28`
- `.net_8.0 >= 8.0.0 < 8.0.28`
- `.net_9.0 >= 9.0.0 < 9.0.17`

## Remediation

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

## Package advisory (CVE-2026-45491)

Affected packages:

- `Microsoft.NETCore.App.Runtime.linux-x64 >= 8.0.0, <= 8.0.27`
- `Microsoft.NETCore.App.Runtime.linux-x64 >= 9.0.0, <= 9.0.16`
- `Microsoft.NETCore.App.Runtime.linux-x64 >= 10.0.0, <= 10.0.8`
- `Microsoft.NETCore.App.Runtime.win-x64 >= 8.0.0, <= 8.0.27`
- `Microsoft.NETCore.App.Runtime.win-x64 >= 9.0.0, <= 9.0.16`
- `Microsoft.NETCore.App.Runtime.win-x64 >= 10.0.0, <= 10.0.8`
- `Microsoft.NETCore.App.Runtime.osx-arm64 >= 8.0.0, <= 8.0.27`
- `Microsoft.NETCore.App.Runtime.osx-arm64 >= 9.0.0, <= 9.0.16`
- `Microsoft.NETCore.App.Runtime.osx-arm64 >= 10.0.0, <= 10.0.8`

Patched in:

- `Microsoft.NETCore.App.Runtime.linux-x64 8.0.28`
- `Microsoft.NETCore.App.Runtime.linux-x64 9.0.17`
- `Microsoft.NETCore.App.Runtime.linux-x64 10.0.9`
- `Microsoft.NETCore.App.Runtime.win-x64 8.0.28`
- `Microsoft.NETCore.App.Runtime.win-x64 9.0.17`
- `Microsoft.NETCore.App.Runtime.win-x64 10.0.9`
- `Microsoft.NETCore.App.Runtime.osx-arm64 8.0.28`
- `Microsoft.NETCore.App.Runtime.osx-arm64 9.0.17`
- `Microsoft.NETCore.App.Runtime.osx-arm64 10.0.9`

Source: https://github.com/advisories/GHSA-7q4v-2mr6-5gpx