CVE-2026-70197: Microsoft Security Advisory CVE-2026-70197 - .NET and Visual Studio Remote Code Execution Vulnerability in nuget Package Mic

Maintainers of Microsoft.NETCore.App.Runtime.win-arm64, a package in the nuget ecosystem, have published a high-severity security advisory (CVE-2026-70197): Microsoft Security Advisory CVE-2026-70197 - .NET and Visual Studio Remote Code Execution Vulnerability.

At a glance

Advisory

GHSA-4mpw-cpwj-hxxj

CVE

CVE-2026-70197

Package

Microsoft.NETCore.App.Runtime.win-arm64 (nuget)

Severity

High

Patched in

8.0.32

What is the issue?

The GitHub-reviewed advisory explains: Executive summary Microsoft is releasing this security advisory to provide information about a vulnerability in System.Net.Sockets. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. On Windows, reusing a SocketAsyncEventArgs instance across IPv4 and IPv6 datagram sockets can retain an undersized cached native address buffer, allowing an unauthenticated out-of-bounds write during ReceiveFromAsync. Announcement Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/466 CVSS Details - Version: 3.1 - Severity: High - Score: 8.1 - Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness: CWE-787 (Out-of-bounds Write) Affected Platforms - Platforms: Windows - Architectures: All <a name="affected-packages"</aAffected Packages The vulnerability affects Microsoft .NET projects that u

Affected versions

The advisory lists a CVSS score of 8.1.

How to fix it

• Upgrade the affected package to the first patched version listed above.
• Rebuild and redeploy applications that bundle the vulnerable dependency.
• Run your dependency scanner (npm audit, pip-audit, Dependabot) to find transitive uses.
• Review the advisory references for workaround details if you cannot upgrade yet.

What to do and how to stay safe: CVE-2026-70197

• Vulnerability severity scores ignore your specific architecture and context.
• Exploitability depends on network exposure and user behavior, not just code flaws.
• Prioritization requires continuous asset inventory and threat intelligence alignment.

Risk-based vulnerability management focuses your limited resources on the flaws that actually threaten your business. Start by mapping your critical assets and checking for active exploits to prioritize your backlog.

Step-by-step guide: Risk-Based Vulnerability Management: Prioritize Fixes by Actual Danger

General security guidance from the Threat Times newsroom. It is not confirmed advice from the organisations named in this story.

Frequently asked questions

What is CVE-2026-70197?

CVE-2026-70197 is a security vulnerability in Microsoft.NETCore.App.Runtime.win-arm64 (nuget).

Which version fixes CVE-2026-70197?

The fix is in version 8.0.32.