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critical·Product Based Web Vulnerabilities·Updated Apr 6, 2026

CVE-2025-59528 Scanner

CVE-2025-59528 Scanner - Remote Code Execution vulnerability in Flowise

Est. Time~10 seconds
Scan TypeSingle Scan
Targetsdomain, subdomain, ipv4
CostFree
3.2k
Times Used
continuous scan runs
5.5k
Continuously Checked
assets under CS
0
Vulnerabilities Found
confirmed findings
References
CVECVE-2025-59528
10.0
CVSScritical
Exploitable remotely over the internet · no authentication required.

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.

Attack Vector
Network
Privileges Req.
None
User Interaction
None
Affected
Flowiseby FlowiseAI
= 3.0.5
Updated Aug 22, 2026View on NVD →
Detail

Flowise is a powerful data stream processing software that is utilized by enterprises to efficiently automate data workflows and handle large volumes of data seamlessly. Often deployed in cloud environments, it enables developers to design data processing applications by providing an intuitive graphical interface. Organizations from various sectors, such as finance, healthcare, and technology, leverage Flowise to improve their operational efficiencies. The software supports integration with Node.js, allowing users to extend its functionalities by incorporating custom scripts. However, the same flexibility introduces vulnerabilities, as seen with the Remote Code Execution (RCE) issue. Regular security assessments and software updates are critical in maintaining the security posture of systems using Flowise.

The Remote Code Execution (RCE) vulnerability detected in Flowise version 3.0.5 is critically dangerous as it allows attackers to run arbitrary code. This flaw exists due to the unsafe evaluation of user inputs within the CustomMCP node's convertToValidJSONString function. When exploited, it grants attackers the capability to execute commands with Node.js privileges. Such vulnerabilities are often targeted by malicious actors to gain unauthorized access or control over a system. The security issue is severe, emphasizing the importance of adopting secure coding practices. Regular updates and user awareness can mitigate risks associated with such vulnerabilities.

The technical root of this vulnerability lies in the mishandling of user inputs in the CustomMCP node's convertToValidJSONString function. The affected endpoint is the customMCP node-load-method, which improperly processes specially crafted payloads. Attackers can execute potentially harmful scripts by sending crafted input like a request with mcpServerConfig set to execute code through child_process. Specifically, the endpoint fails to correctly sanitize user inputs, allowing for command injection and execution within the Node.js runtime environment. The ability to utilize interactsh to test the vulnerability indicates its accessibility and exploitability. Effective containment requires fixing the input validation logic within the application endpoint.

If exploited, this Remote Code Execution vulnerability can have devastating effects, leading to full system compromise. Malicious actors can gain complete control over the affected system by executing arbitrary commands. This can result in unauthorized data access, data loss, or even service disruptions across enterprise-level applications. Furthermore, exploiting such critical vulnerabilities could potentially lead to lateral movement within an organization's network, escalating cyber threats to other systems. The financial and reputational consequences for an organization can be substantial, necessitating immediate actions upon detecting this vulnerability. Preventive measures, such as backward compatibility checks and regular security updates, play a vital role in averting such severe impacts.

REFERENCES

Solution Advice
  • Immediately update Flowise to version 3.0.6 or later to patch the vulnerability.
  • Regularly review and apply security patches to ensure systems are protected against known vulnerabilities.
  • Conduct thorough security testing on custom scripts and user inputs to prevent unsafe evaluations.
  • Implement strict access controls and monitoring to identify and mitigate unauthorized activities promptly.
  • Educate users on safe usage practices and potential security risks associated with RCE vulnerabilities.

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