CVE-2026-62909: CVE-2026-62909: .NET Local Elevation of Privilege via Unchecked Diagnostic Socket Permissions

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CVE-2026-62909: .NET Local Elevation of Privilege via Unchecked Diagnostic Socket Permissions

Vulnerability ID: CVE-2026-62909
CVSS Score: 7.8
Published: 2026-08-11

A high-severity Local Elevation of Privilege (EoP) vulnerability exists in the Microsoft .NET runtime and Visual Studio on Unix-like platforms. The flaw arises from an unchecked return value (CWE-252) during the initialization of the Diagnostics Inter-Process Communication (IPC) socket. By exploiting this vulnerability, a low-privileged local attacker can execute arbitrary commands with the privileges of a higher-privileged .NET process.

TL;DR

An unchecked return value on permission-setting system calls for Unix Domain Sockets in the .NET runtime allows local privilege escalation to root on macOS and Linux.

Technical Details

CWE ID: CWE-252
Attack Vector: Local (AV:L)
CVSS: 7.8 (High)
Impact: Local Elevation of Privilege
Exploit Status: None (No weaponized public PoCs)
KEV Status: Not listed

Affected Systems

.NET 10.0
.NET 9.0
.NET 8.0
Visual Studio 2022
Visual Studio 2026

Mitigation Strategies

Upgrade the .NET runtime environment to a non-vulnerable servicing release.
Apply restrictive process umask policies (0077) to ensure safe default socket creation parameters.
Relocate diagnostic socket generation folders to directories with restricted user-only access.
Disable the .NET diagnostics server endpoint completely in workloads where debugging is not required.

Remediation Steps:

Identify active .NET deployment runtimes across Unix-like container hosts and Virtual Machines.
Apply the platform-specific patch updating .NET 10.0 to 10.0.11, .NET 9.0 to 9.0.19, or .NET 8.0 to 8.0.30.
For temporary containment, set the system environment variable DOTNET_EnableDiagnostics=0 on production hosts.