Arbitrary Code Injection Affecting microsoft.aspnetcore.components.webassembly.server package, versions [10.0.0,10.0.13)[11.0.0-preview.1,11.0.0-rc.2.26478.115)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DOTNET-MICROSOFTASPNETCORECOMPONENTSWEBASSEMBLYSERVER-20936768
- published14 Oct 2026
- disclosed13 Oct 2026
- creditalittleston3
Introduced: 13 Oct 2026
NewCVE-2026-102870 (opens in a new tab)How to fix?
Upgrade Microsoft.AspNetCore.Components.WebAssembly.Server to version 10.0.13, 11.0.0-rc.2.26478.115 or higher.
Overview
Microsoft.AspNetCore.Components.WebAssembly.Server is a runtime server features for ASP.NET Core Blazor applications that have a client running under WebAssembly.
Affected versions of this package are vulnerable to Arbitrary Code Injection in the Blazor WebAssembly debug proxy when evaluating debugger expressions that generate and compile C# source. An attacker can execute arbitrary code on a developer's machine by supplying specially crafted values, such as manipulated ToString() results, descriptions, or class names, that escape the generated string literal during debugging. This is only exploitable if a developer debugs a Blazor WebAssembly application and evaluates an expression involving attacker-controlled application data.