Flowise MCP RCE: What CVE-2026-40933 Teaches About Agent Security

Flowise MCP RCE is not just another patch note. It is a warning about how agent builders handle Model Context Protocol servers, especially STDIO-based tools. The full TokenMix.ai version is here: Flowise MCP RCE: 10 Fixes for CVE-2026-40933 and Upsonic . Short version: Patch Flowise to 3.1.0 or later. Patch Upsonic to 0.72.0 or later. Do not treat MCP STDIO as harmless configuration. Do not rely on input sanitization as the main control. Treat any user-configurable STDIO MCP server like a proces