CVE-2026-82456: argocd-mcp 0.8.0 Authentication Bypass via Unauthenticated HTTP
argocd-mcp 0.8.0 binds its HTTP transport to every network interface and accepts MCP sessions without requiring caller credentials when ARGOCDAPITOKEN is configured. Attackers who can reach the listener can invoke the full tool surface using the operator's stored token to create applications, request syncs, and modify Argo CD resources.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
In argocd-mcp 0.8.0, limit the HTTP transport binding so the listener is not exposed on every network interface; bind only to the specific interface(s) needed.
argocd-mcp HTTP transport bind address / interface = Bind only to required network interfaces (avoid 0.0.0.0 / all interfaces) - Configuration
In argocd-mcp 0.8.0, ensure MCP sessions over HTTP require caller credentials even when ARGOCD_API_TOKEN is configured; do not allow unauthenticated sessions.
argocd-mcp MCP session authentication requirement when ARGOCD_API_TOKEN is configured = Require caller credentials (do not accept unauthenticated MCP sessions) - Compensating control
Restrict network access to the argocd-mcp HTTP listener so that only trusted clients can reach the listener (e.g., firewall/ACL allowlisting of source IPs/ports).