CVE-2025-59528 — CRITICAL (10.0)

Vulnerability 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.

CVSS Score

10.0

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

CHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

Affected Products

Vendor	Product	Versions
Flowiseai	Flowise	3.0.5

Related Weaknesses (CWE)

CWE-94

References

FAQ

What is CVE-2025-59528?

CVE-2025-59528 is a vulnerability with a CVSS score of 10.0 (CRITICAL). 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 conf...

How severe is CVE-2025-59528?

CVE-2025-59528 has been rated CRITICAL with a CVSS base score of 10.0/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2025-59528?

Check the references section above for vendor advisories and patch information. Affected products include: Flowiseai Flowise.