CVE-2025-59528

Description

Flowise is a drag & drop user interface to build a customized large language model flow. In version 3.0.5, Flowise is vulnerable to remote code execution. The CustomMCP node allows users to input configuration settings for connecting to an external MCP server. This node parses the user-provided mcpServerConfig string to build the MCP server configuration. However, during this process, it executes JavaScript code without any security validation. Specifically, inside the convertToValidJSONString function, user input is directly passed to the Function() constructor, which evaluates and executes the input as JavaScript code. Since this runs with full Node.js runtime privileges, it can access dangerous modules such as child_process and fs. This issue has been patched in version 3.0.6.

References

https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-3gcm-f6qx-ff7p

https://github.com/FlowiseAI/Flowise/releases/tag/flowise%403.0.6

https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/services/nodes/index.ts#L91-L94

https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/routes/node-load-methods/index.ts#L5

https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/controllers/nodes/index.ts#L57-L78

https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L262-L270

https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L220

https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L132

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

EPSS