Findings

CVE-2026-102870

Microsoft Security Advisory CVE-2026-102870 - ASP.NET Core Remote Code Execution Vulnerability

Published Oct 13, 2026

Microsoft is releasing this security advisory to provide information about a vulnerability in the Blazor WebAssembly debugger included in Microsoft.AspNetCore.Components.WebAssembly.Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. The Blazor WebAssembly debug proxy evaluates debugger expressions by generating and compiling C# source. Certain values originating in the application being debugged, including ToString() results, descriptions, and class names, are embedded in …

Timeline

Detection, updates, and resolution for this record.

  1. Oct 13, 2026 · GitLab Advisory Database

    Detected

    Microsoft is releasing this security advisory to provide information about a vulnerability in the Blazor WebAssembly debugger included in Microsoft.AspNetCore.Components.WebAssembly.Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. The Blazor WebAssembly debug proxy evaluates debugger expressions by generating and comp

Affected

  • nuget microsoft.aspnetcore.components.webassembly.serverversion unspecified

Sources

  • CVE.orgCVE-2026-102870

    Official CVE identifier

    cve.org
  • FIRST EPSSCVE-2026-102870

    30-day exploitation probability 0.8%

    first.org
  • Microsoft is releasing this security advisory to provide information about a vulnerability in the Blazor WebAssembly debugger included in Microsoft.AspNetCore.Components.WebAssembly.Server. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. The Blazor WebAssembly debug proxy evaluates debugger expressions by generating and comp

    advisories.gitlab.com