argocd-mcp version 0.8.0 contains a critical authentication bypass vulnerability where its HTTP transport binds to all network interfaces and accepts MCP sessions without requiring caller credentials when ARGOCD_API_TOKEN is configured. Any attacker who can reach the listener can leverage the operator's stored token to invoke the full tool surface. This allows unauthorized creation of applications, requesting syncs, and modification of Argo CD resources. The vulnerability effectively grants full operator-level access to any network-reachable attacker. No authentication is enforced on incoming MCP session requests despite sensitive token configuration being present. This poses a significant risk in any environment where the service is exposed beyond localhost.
