CVE-2026-120006: Elevation of Privilege in .NET Aspire via Unintended Dashboard Endpoint Tunneling

Vulnerability ID: CVE-2026-120006
CVSS Score: 7.5
Published: 2026-11-10

An elevation of privilege vulnerability exists in .NET Aspire versions prior to 13.6.5 due to the insertion of sensitive information into sent data (CWE-201). When the Developer Control Plane (DCP) container tunneling feature is enabled, the orchestration engine implicitly exposes all endpoints of the Aspire Dashboard—including its administrative frontend and management APIs—to containerized workloads instead of restricting tunnel access solely to OpenTelemetry Protocol (OTLP) collection endpoints. This exposure allows an attacker operating within a compromised or untrusted container to query the dashboard frontend, extract sensitive environment variables and connection strings, and elevate privileges across the host orchestration boundary.

TL;DR

.NET Aspire prior to 13.6.5 automatically tunnels the administrative dashboard frontend into container networks when container tunneling is enabled, allowing compromised containers to read sensitive host secrets and escalate privileges.

Technical Details

• CVE ID: CVE-2026-120006
• Weakness Class: CWE-201 (Insertion of Sensitive Information Into Sent Data)
• CVSS v3.1 Score: 7.5 High (CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H)
• Attack Vector: Local / Container Network Namespace (AV:L)
• Affected Component: Aspire.Hosting & Aspire.Hosting.AppHost (< 13.6.5)
• Patched Version: .NET Aspire 13.6.5
• Exploit Status: Unproven / No Public PoC
• CISA KEV Status: Not Listed

Affected Systems

• Microsoft .NET Aspire (Aspire.Hosting)
• Microsoft .NET Aspire (Aspire.Hosting.AppHost)
• Aspire.Hosting: < 13.6.5 (Fixed in: 13.6.5)
• Aspire.Hosting.AppHost: < 13.6.5 (Fixed in: 13.6.5)

Code Analysis

Commit: f017f66

Merged PR 68055: Limit automatic dashboard tunnelling to OTLP endpoints. Preserves explicit dashboard endpoint references and ordinary host-resource tunneling. Normalizes legacy host URLs into endpoint references at the dependency-discovery boundary.

if (_options.Value.EnableAspireContainerTunnel)
{
    var dashboardIndex = hostDependencies.FindIndex(dependency =>
        StringComparers.ResourceName.Equals(dependency.Resource.Name, KnownResourceNames.AspireDashboard));
    if (dashboardIndex >= 0)
    {
        // Telemetry must not implicitly expose the dashboard frontend. Preserve explicit endpoint
        // references without narrowing the endpoints exposed for ordinary host dependencies.
        var dashboard = hostDependencies[dashboardIndex];
        var endpoints = await GetDashboardTunnelEndpointsAsync(resource, dashboard, cancellationToken).ConfigureAwait(false);
        hostDependencies.RemoveAll(dependency =>
            StringComparers.ResourceName.Equals(dependency.Resource.Name, KnownResourceNames.AspireDashboard));
        if (endpoints.Length > 0)
        {
            hostDependencies.Add(new HostResourceWithEndpoints(dashboard.Resource, endpoints));
        }
    }
}

Mitigation Strategies

• Upgrade .NET Aspire hosting packages (Aspire.Hosting and Aspire.Hosting.AppHost) to version 13.6.5 or later.
• Disable automatic container tunneling by setting EnableAspireContainerTunnel to false in DcpOptions when host-to-container proxy tunnels are not required.
• Enforce strong authentication on the .NET Aspire Dashboard frontend and restrict container network egress to non-essential host ports.
• Sanitize sensitive environment variables, connection strings, and bearer tokens before emitting OpenTelemetry spans and structured logs.

Remediation Steps:

1. Locate all .csproj or Directory.Packages.props files within the solution that reference Aspire.Hosting or Aspire.Hosting.AppHost.
2. Update the Version attribute for both Aspire.Hosting and Aspire.Hosting.AppHost to 13.6.5 or higher.
3. Execute 'dotnet restore' and rebuild the application host project to link against the patched assemblies.
4. Restart any running .NET Aspire AppHost orchestration sessions and verify that container tunnels only bind OTLP ports (4317/4318) unless explicitly referenced.

References

• Microsoft Security Response Center: CVE-2026-120006
• CVE.org Record: CVE-2026-120006
• GitHub Commit: Limit automatic dashboard tunnelling to OTLP endpoints
• GitHub Release: .NET Aspire v13.6.5

Read the full report for CVE-2026-120006 on our website for more details including interactive diagrams and full exploit analysis.