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

[ Description ]Official description

Improper control of generation of code ('code injection') in ASP.NET Core allows an unauthorized attacker to execute code over a network.

[ Fixes ]Fixes and patches

• Microsoft.AspNetCore.Components.WebAssembly.Server 10.0.13Fixed version · GitHub Advisories · nuget package Microsoft.AspNetCore.Components.WebAssembly.Server: upgrade to 10.0.13 or later (affected >= 10.0.0, <= 10.0.12)
• Microsoft.AspNetCore.Components.WebAssembly.Server 11.0.0-rc.2.26478.115Fixed version · GitHub Advisories · nuget package Microsoft.AspNetCore.Components.WebAssembly.Server: upgrade to 11.0.0-rc.2.26478.115 or later (affected >= 11.0.0-preview.1, <= 11.0.0-rc.1)

[ Advisories ]Government CERT advisories

• CERT-FR14 Oct 2026CERTFR-2026-AVI-1316

  Multiple vulnerabilities in Microsoft products Translated from French

  Multiple vulnerabilities have been discovered in Microsoft products. Some of them allow an attacker to cause remote arbitrary code execution, privilege escalation and remote denial of service.

  CVE-2026-88086CVE-2026-70007CVE-2026-70179+141 more CVEs
• BSI CERT-Bund13 Oct 2026WID-SEC-2026-3893

  Microsoft Entwicklerwerkzeuge: Multiple vulnerabilities Translated from German

  Risk highCVE-2026-96230CVE-2026-84008CVE-2026-102238+64 more CVEs
• NCSC-NL13 Oct 2026NCSC-2026-0426

  Vulnerabilities fixed in Microsoft Developer Tools Translated from Dutch

  Probability/damage M/HCVE-2026-58280CVE-2026-66822CVE-2026-69370+59 more CVEs

[ Packages ]Affected open-source packages

• Microsoft.AspNetCore.Components.WebAssembly.Server nugetAffected >= 10.0.0, <= 10.0.12 · fixed in 10.0.13 · GHSA-g27p-qf6j-c96c
• Microsoft.AspNetCore.Components.WebAssembly.Server nugetAffected >= 11.0.0-preview.1, <= 11.0.0-rc.1 · fixed in 11.0.0-rc.2.26478.115 · GHSA-g27p-qf6j-c96c

[ References ]References

• msrc.microsoft.com/update-guide/vulnerability/CVE-2026-102870