GitHub Security Advisory: GHSA-crjq-wm6x-6qx7
Package: Microsoft.NetCore.App.Runtime.linux-musl-arm (NUGET)
Severity: HIGH (CVSS 7.8)
CWE: CWE-276: Incorrect Default Permissions
Vulnerable versions: >= 10.0.0, <= 10.0.3
Patched in: 10.0.4

Summary: .NET Elevation of Privilege Vulnerability

Details:
# Microsoft Security Advisory CVE-2026-26131 – .NET Elevation of Privilege Vulnerability

## Executive summary

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

An elevation of privilege vulnerability exists in .NET due to improper authorization. Incorrect packaging permissions could allow an attacker to gain elevated privileges.

## Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/386

## CVSS Details

- **Severity:** High
- **Version:** 3.1
- **Score:** 7.8
- **Vector:** `CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C`
- **Weakness:** CWE-276 (Incorrect Default Permissions)

## Affected Platforms

- **Platforms:** Linux
- **Architectures:** All

## Affected Products

### <a name=".NET 10"></a>.NET 10
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.NetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm)               | >= 10.0.0, <= 10.0.3 | 10.0.4
[Microsoft.NetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm64)           | >= 10.0.0, <= 10.0.3 | 10.0.4
[Microsoft.NetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm)     | >= 10.0.0, <= 10.0.3 | 10.0.4
[Microsoft.NetCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm64) | >= 10.0.0, <= 10.0.3 | 10.0.4
[Microsoft.NetCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-x64)     | >= 10.0.0, <= 10.0.3 | 10.0.4
[Microsoft.NetCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-x64)               | >= 10.0.0, <= 10.0.3 | 10.0.4

## Advisory FAQ

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

If using an affected package listed in [affected products](#affected-products), you're 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 .NET 10.0. If you have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt you to update Visual Studio, which will also update your .NET  SDKs.
2. If your application references the vulnerable package, update the package reference to the patched version. You can list the versions you have installed by running the `dotnet --info` command. 

Once you have installed the updated runtime or SDK, restart your apps for the update to take effect.

Additionally, if you've deployed [self-contained applications](https://docs.microsoft.com/dotnet/core/deploying/#self-contained-deployments-scd) targeting any of the impacted versions, thes