FlowiseAI Flowise 3.0.5 convertToValidJSONString code injection

Summaryinfo

A vulnerability identified as critical has been detected in FlowiseAI Flowise 3.0.5. This impacts the function convertToValidJSONString. The manipulation leads to code injection. This vulnerability is referenced as CVE-2025-59528. Remote exploitation of the attack is possible. Furthermore, an exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in FlowiseAI Flowise 3.0.5. It has been rated as critical. This issue affects the function convertToValidJSONString. The manipulation with an unknown input leads to a code injection vulnerability. Using CWE to declare the problem leads to CWE-94. The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2025-59528 since 09/17/2025. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details as well as a public exploit are known. MITRE ATT&CK project uses the attack technique T1059 for this issue.

The exploit is available at exploit-db.com. It is declared as proof-of-concept.

Upgrading to version 3.0.6 eliminates this vulnerability.

The vulnerability is also documented in the databases at Exploit-DB (52440) and EUVD (EUVD-2025-29246). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• FlowiseAI

Name

• Flowise

Version

• 3.0.5

Website

• Product: https://github.com/FlowiseAI/Flowise/

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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