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Argo CD MCP: unauthenticated cluster access

An investigation into the authentication boundary between an AI tool and the infrastructure it controls.

Open the original ↗Original Apiiro cover for the Argo CD MCP vulnerability article

Security research · CVE-2026-82456

Where does an unauthenticated request stop?

A small, visual comparison of the Argo CD MCP server boundary: in the affected release, reachable HTTP transport could lead into configured credentials and deployment tools.

Unauthenticated traffic can cross the server boundary.

  1. 01CallerNo inbound credential
  2. 02MCP serverHTTP transport
  3. 03Argo CDConfigured token
  4. 04KubernetesDeployment tools

Ready to trace the request path.

Simplified illustration · no network requests

What changed in 0.9.0? The fixed release adds token authentication and binds the server to localhost by default.

This is an authentication-boundary comparison, not a claim that token checks alone solve every deployment risk.

Read the public research source

The authentication boundary

The affected Argo CD MCP server accepted unauthenticated HTTP requests and reused its configured Argo CD credential. A caller able to reach that transport could invoke deployment operations through the server.

The published Apiiro investigation documents the affected configuration, reproduction, disclosure timeline, and remediation. It also covers a separate prompt-injection path through an agent with access to the tools.

The network demonstration required a reachable HTTP transport and a configured Argo CD credential. The maintainer advisory is GHSA-rp45-5x3v-48mr; the full article explains these prerequisites and the fix.