CVE-2026-26130: .NET Denial of Service Vulnerability

March 11, 2026

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 denial of service vulnerability exists in ASP.NET Core due to uncontrolled resource consumption. A specially crafted message to a SignalR server can exhaust an internal buffer and cause a Denial of Service.

References

github.com/advisories/GHSA-4vgm-c2wm-63mw
github.com/dotnet/aspnetcore
github.com/dotnet/aspnetcore/security/advisories/GHSA-4vgm-c2wm-63mw
msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26130
nvd.nist.gov/vuln/detail/CVE-2026-26130
www.cve.org/CVERecord?id=CVE-2026-26130

Code Behaviors & Features

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