Active Exploitation of Critical Flowise Vulnerability

Security researchers have confirmed that threat actors are actively exploiting a critical vulnerability in the open-source Flowise platform, allowing remote code execution on affected systems. The flaw, tracked as CVE-2025-59528 and rated at the maximum severity of CVSS 10.0, was first disclosed in September 2024 and patched months ago, yet exploitation attempts emerged in early April 2025.

Flowise is a low-code development tool that enables users to create customized large language model workflows and autonomous AI agents through a drag-and-drop interface. It supports building pipelines for applications such as chatbots, automation systems, and AI-driven processes, often integrating external tools and APIs. The vulnerability resides in the platform's Custom MCP node, which facilitates connections to external Model Context Protocol servers. According to the advisory, this node processes user-supplied configuration strings, known as mcpServerConfig, without proper validation. Specifically, the convertToValidJSONString function passes the input directly to JavaScript's Function constructor, evaluating and executing it with full Node.js runtime privileges. This grants attackers...