GHSA-55jh-fwmh-39m4: Microsoft Security Advisory CVE-2026-50526 – .NET Tampering Vulnerability

Executive summary Microsoft is releasing this security advisory to provide information about a vulnerability in .NET SDK (Microsoft.NET.Build.Containers). This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A tampering vulnerability exists in the .NET SDK (.NET 8, .NET 9, and .NET 10) container image build process which could allow a local attacker to inject resources that could be incorporated into container images built by other users on the same machine. Announcement Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/TBD CVSS Details - Version: 3.1 - Severity: High - Score: 7.0 - Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness: CWE-59 (Improper Link Resolution Before File Access ('Link Following')) Affected Platforms - Platforms: All - Architectures: All <a name="affected-packages"></a>Affected Packages The vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below <a name=".NET 10.0"></a>.NET 10.0 Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.NET.Build.Containers | >= 10.0.0, <= 10.0.9 | 10.0.10 <a name=".NET 9.0"></a>.NET 9.0 Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.NET.Build.Containers | >= 9.0.0, <= 9.0.17 | 9.0.18 <a name=".NET 8.0"></a>.NET 8.0 Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.NET.Build.Containers | >= 8.0.0, <= 8.0.28 | 8.0.29 Advisory FAQ <a name="how-affected"></a>How do I know if I am affected? If using a package listed in affected packages, you're exposed to the vulnerability. <a name="how-fix"></a>How do I fix the issue? 1. To fix the issue please install the latest version of .NET. If you have installed one or more .NET SDKs thr