CVE-2026-120006

## Executive summary Microsoft is releasing this security advisory to provide information about a vulnerability in Aspire. This advisory provides guidance on updating affected applications and components. Disclosure of an Aspire Dashboard authentication cookie to a linked service can allow an attacker-controlled container to replay the authenticated session and execute code as the host developer. ## Announcement Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/503 ## CVSS Details - **Version:** 3.1 - **Severity:** High - **Score:** 7.5 - **Vector:** `CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H` - **Weakness:** CWE-201 (Insertion of Sensitive Information Into Sent Data) ## Affected Platforms - **Platforms:** macOS - **Architectures:** x64, Arm64 ## <a name="affected-packages"></a>Affected Packages ### Standalone Aspire Package | Affected version | Patched version --- | --- | --- [Aspire.Hosting.AppHost](https://www.nuget.org/packages/Aspire.Hosting.AppHost) | < 13.6.5 | 13.6.5 [Aspire.Hosting](https://www.nuget.org/packages/Aspire.Hosting) | < 13.6.5 | 13.6.5 The affected scenario involves a Dashboard-authenticated AppHost workflow with an attacker-controlled container and a linked HTTPS YARP gateway. The affected hosting code is in `Aspire.Hosting`, a dependency of `Aspire.Hosting.AppHost`. `Aspire.AppHost.Sdk` supplies the AppHost package implicitly unless the project overrides the default references. ## Advisory FAQ ### <a name="how-affected"></a>How do I know if I am affected? The reported scenario involves a developer starting an Aspire AppHost, authenticating to its Dashboard, and following a resource link that routes to an attacker-controlled container. All released versions through 13.6.4 are affected. Aspire ships independently of .NET. Installing a .NET runtime or SDK update does not establish that the affected Aspire components have been updated. ### <a name="how-fix"></a>How do I fix the issue?