CVE-2026-47303 Microsoft CVE debrief

Who should care

Developers and administrators using ASP.NET Core, .NET, Visual Studio 2022, and Visual Studio 2026 should be aware of this vulnerability and take necessary actions to mitigate it. They should review and update their installations, monitor for suspicious activity, and implement additional security measures.

Technical summary

The vulnerability is caused by authentication bypass by assumed-immutable data in ASP.NET Core. An authorized attacker can exploit this vulnerability to elevate privileges over a network. The CVSS vector is CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. This vulnerability affects Microsoft .NET, Visual Studio 2022, and Visual Studio 2026.

Defensive priority

High priority should be given to patching affected systems, especially those exposed to the internet. Additional security measures such as network segmentation and access controls should be implemented.

Recommended defensive actions

• Apply patches provided by Microsoft
• Review and update .NET, Visual Studio 2022, and Visual Studio 2026 installations
• Monitor for suspicious activity
• Implement additional security measures such as network segmentation and access controls
• Review compensating controls for exposed systems while remediation is scheduled and verified

Evidence notes

The CVE record was published on 2026-07-14T19:17:08.707Z and was last modified on 2026-07-22T21:17:15.777Z. The NVD entry is currently Analyzed. This information is based on the NVD entry and CVE record. The vulnerability affects Microsoft .NET, Visual Studio 2022, and Visual Studio 2026. There is no evidence of exploitation in the wild, but an authorized attacker can exploit this vulnerability to elevate privileges over a network.

Official resources