What is the CVSS score of CVE-2025-59528?

CVE-2025-59528 has a CVSS 3.1 base score of 10.0 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H. EPSS exploitation probability: 83.0%.

Which versions of Node.js are affected by CVE-2025-59528?

Organizations using Flowise face critical risk from CVE-2025-59528, a code injection vulnerability rated CVSS 10.0.. A patch is available.

Is there a public PoC exploit available for CVE-2025-59528?

Yes, a public proof-of-concept exploit is available for CVE-2025-59528. Prioritise patching immediately. EPSS: 83.0%.

How to fix or mitigate CVE-2025-59528?

Within 24 hours: Identify all affected systems and apply vendor patches immediately. Validate that input sanitization is in place for all user-controlled parameters.

Node.js CVE-2025-59528

CRITICAL

Code Injection (CWE-94)

2025-09-22 security-advisories@github.com

RCE Code Injection Node.js Flowise

10.0

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

10.0 CRITICAL

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

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

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

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

Analysis Generated

Mar 28, 2026 - 19:13 vuln.today

PoC Detected

Sep 23, 2025 - 16:45 vuln.today

Public exploit code

CVE Published

Sep 22, 2025 - 20:15 nvd

CRITICAL 10.0

DescriptionGitHub Advisory

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.

AnalysisAI

Flowise version 3.0.5 contains a remote code execution vulnerability in the CustomMCP node. The mcpServerConfig parameter is parsed unsafely, allowing attackers to inject arbitrary system commands through the MCP server configuration that are executed when Flowise spawns the MCP server process.

Technical ContextAI

The CustomMCP node allows users to configure connections to external MCP (Model Context Protocol) servers. The mcpServerConfig string is parsed and used to construct a command-line invocation to spawn the MCP server process. The parser fails to sanitize shell metacharacters in the configuration values, allowing injection of arbitrary commands that execute when the MCP server is started.

RemediationAI

Update to Flowise 3.0.6 or later. Enable authentication on Flowise instances. Validate and sanitize mcpServerConfig inputs using an allowlist of permitted commands. Run Flowise in a container with restricted filesystem and network access.