$ cve CVE-2025-59528 JSON

CVE-2025-59528 EXPLOIT

10.0

CRITICAL · CVSS 3.1 · EPSS 86.2% (pctl 100)

Patch early

A public exploit exists.

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.

Scoring

CVSS	10.0 (CRITICAL, v3.1)
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS	86.22% — more likely to be exploited than 100% of all CVEs
Weakness	CWE-94
On CISA KEV	no
Public exploit	yes
Published	2025-09-22
Last modified	2026-06-17

Affected (1)

Vendor	Product
flowiseai	flowise

Public exploits

Source	Title	Date
exploit-db	Flowise 3.0.4 - Remote Code Execution (RCE)	2025-10-31

References

→ the Explorer · watch your stack · NVD