CVE-2026-32175

A tampering vulnerability exists when .NET Core improperly handles specially crafted files. An attacker who successfully exploited this vulnerability could write arbitrary files and directories to certain locations on a vulnerable system. However, an attacker would have limited control over the destination of the files and directories. To exploit the vulnerability, an attacker must send a specially crafted file to a vulnerable system. The security update fixes the vulnerability by ensuring .NET Core properly handles files.

A tampering vulnerability exists when .NET Core improperly handles specially crafted files. An attacker who successfully exploited this vulnerability could write arbitrary files and directories to certain locations on a vulnerable system. However, an attacker would have limited control over the destination of the files and directories. To exploit the vulnerability, an attacker must send a specially crafted file to a vulnerable system. The security update fixes the vulnerability by ensuring .NET Core properly handles files.

Executive Summary:

Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 8.0, .NET 9.0, and .NET 10.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

A tampering vulnerability exists when .NET Core improperly handles specially crafted files. An attacker who successfully exploited this vulnerability could write arbitrary files and directories to certain locations on a vulnerable system. However, an attacker would have limited control over the destination of the files and directories.

To exploit the vulnerability, an attacker must send a specially crafted file to a vulnerable system.

The security update fixes the vulnerability by ensuring .NET Core properly handles files.

Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/396

CVSS Details

• Version: 3.1
• Severity:
• Score: 4.3
• Vector: /AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
• Weakness: CWE-36: Absolute Path Traversal

Affected Platforms

• Platforms: Windows
• Architectures: All

<a name="affected-packages"></a>Affected Packages

The vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below

<a name=".NET 10"></a>.NET 10

Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.NetCore.App.Runtime.win-arm | >= 10.0.0, <= 10.0.7 | 10.0.8 Microsoft.NetCore.App.Runtime.win-arm64 | >= 10.0.0, <= 10.0.7 | 10.0.8 Microsoft.NetCore.App.Runtime.win-x64 | >= 10.0.0, <= 10.0.7 | 10.0.8 Microsoft.NetCore.App.Runtime.win-x86 | >= 10.0.0, <= 10.0.7 | 10.0.8

<a name=".NET 9"></a>.NET 9

Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.NetCore.App.Runtime.win-arm | >= 9.0.0, <= 9.0.15 | 9.0.16 Microsoft.NetCore.App.Runtime.win-arm64 | >= 9.0.0, <= 9.0.15 | 9.0.16 Microsoft.NetCore.App.Runtime.win-x64 | >= 9.0.0, <= 9.0.15 | 9.0.16 Microsoft.NetCore.App.Runtime.win-x86 | >= 9.0.0, <= 9.0.15 | 9.0.16

<a name=".NET 8"></a>.NET 8

Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.NetCore.App.Runtime.win-arm | >= 8.0.0, <= 8.0.26 | 8.0.27 Microsoft.NetCore.App.Runtime.win-arm64 | >= 8.0.0, <= 8.0.26 | 8.0.27 Microsoft.NetCore.App.Runtime.win-x64 | >= 8.0.0, <= 8.0.26 | 8.0.27 Microsoft.NetCore.App.Runtime.win-x86 | >= 8.0.0, <= 8.0.26 | 8.0.27

Advisory FAQ

<a name="how-affected"></a>How do I know if I am affected?

If using a package listed in affected packages, a developer's application is exposed to the vulnerability.

<a name="how-fix"></a>How do I fix the issue?

1. To fix the issue please install the latest version of…

A tampering vulnerability exists when .NET Core improperly handles specially crafted files. An attacker who successfully exploited this vulnerability could write arbitrary files and directories to certain locations on a vulnerable system. However, an attacker would have limited control over the destination of the files and directories. To exploit the vulnerability, an attacker must send a specially crafted file to a vulnerable system. The security update fixes the vulnerability by ensuring .NET Core properly handles files.

A tampering vulnerability exists when .NET Core improperly handles specially crafted files. An attacker who successfully exploited this vulnerability could write arbitrary files and directories to certain locations on a vulnerable system. However, an attacker would have limited control over the destination of the files and directories. To exploit the vulnerability, an attacker must send a specially crafted file to a vulnerable system. The security update fixes the vulnerability by ensuring .NET Core properly handles files.