Description
Improper certificate validation in .NET Framework allows an unauthorized attacker to bypass a security feature over a network.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Microsoft | .NET 11.0 runtime | 11.0.0 – < 11.0.0-rc.2 | 11.0.0-rc.2 |
| Microsoft | Microsoft Visual Studio 2022 version 17.14 | 17.14.0 – < 17.14.42 | 17.14.42 |
| Microsoft | Microsoft Visual Studio 2026 version 18.10 | 18.10.0 – < 18.10.4 | 18.10.4 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | dotnet10 | 10.0.113-10.0.13-0ubuntu1~26.10.1 | USN-8942-1 |
| Ubuntu 26.10 | dotnet11 | 11.0.100-11.0.0~rc2-0ubuntu1~26.10.1 | USN-8942-1 |
| Ubuntu 26.04 LTS | dotnet10 | 10.0.113-10.0.13-0ubuntu1~26.04.1 | USN-8942-1 |
| Ubuntu 24.04 LTS | dotnet10 | 10.0.113-10.0.13-0ubuntu1~24.04.1 | USN-8942-1 |
| Ubuntu 24.04 LTS | dotnet8 | 8.0.132-8.0.32-0ubuntu1~24.04.1 | USN-8942-1 |
| Ubuntu 22.04 LTS | dotnet7 | No fix yet | — |
| Ubuntu 22.04 LTS | dotnet8 | 8.0.132-8.0.32-0ubuntu1~22.04.1 | USN-8942-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| NuGet | Microsoft.NETCore.App.Runtime.linux-arm | >= 11.0.0-preview.1, < 11.0.0-rc.2 | 11.0.0-rc.2 | GHSA-fqpq-cx42-9jmm |
| NuGet | Microsoft.NETCore.App.Runtime.linux-arm64 | >= 11.0.0-preview.1, < 11.0.0-rc.2 | 11.0.0-rc.2 | GHSA-fqpq-cx42-9jmm |
| NuGet | Microsoft.NETCore.App.Runtime.linux-musl-arm | >= 11.0.0-preview.1, < 11.0.0-rc.2 | 11.0.0-rc.2 | GHSA-fqpq-cx42-9jmm |
| NuGet | Microsoft.NETCore.App.Runtime.linux-musl-arm64 | >= 11.0.0-preview.1, < 11.0.0-rc.2 | 11.0.0-rc.2 | GHSA-fqpq-cx42-9jmm |
| NuGet | Microsoft.NETCore.App.Runtime.linux-musl-x64 | >= 11.0.0-preview.1, < 11.0.0-rc.2 | 11.0.0-rc.2 | GHSA-fqpq-cx42-9jmm |
| NuGet | Microsoft.NETCore.App.Runtime.linux-x64 | >= 11.0.0-preview.1, < 11.0.0-rc.2 | 11.0.0-rc.2 | GHSA-fqpq-cx42-9jmm |
| NuGet | Microsoft.NETCore.App.Runtime.osx-arm64 | >= 11.0.0-preview.1, < 11.0.0-rc.2 | 11.0.0-rc.2 | GHSA-fqpq-cx42-9jmm |
| NuGet | Microsoft.NETCore.App.Runtime.osx-x64 | >= 11.0.0-preview.1, < 11.0.0-rc.2 | 11.0.0-rc.2 | GHSA-fqpq-cx42-9jmm |
Advisories 4
- WID-SEC-2026-3893 Microsoft Entwicklerwerkzeuge: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 4, 2026
- USN-8942-1 dotnet8, dotnet10, dotnet11 vulnerabilities Ubuntu Security Notices (USN) · Oct 30, 2026
- NCSC-2026-0426 Kwetsbaarheden verholpen in Microsoft Developer Tools NCSC-NL (Netherlands) · Oct 13, 2026
- MSRC-CVE-2026-70194 .NET Framework Security Feature Bypass Vulnerability Microsoft Security Response Center · Oct 13, 2026
References
- .NET Framework Security Feature Bypass Vulnerability vendor-advisory patch