CVE-2025-59528: Flowise Remote Code Execution Vulnerability

Q: What is CVE-2025-59528?

CVE-2025-59528 is a security vulnerability in Flowise involving Flowise has Remote Code Execution vulnerability under CWE-94: Improper Control of Generation of Code ('Code Injection').

Q: Which Flowise versions are affected?

Affected versions include releases prior to 3.0.6 across affected packages: flowise.

Q: What version fixes CVE-2025-59528?

Upgrading to 3.0.6 (or the latest patched release for your respective branch) resolves the vulnerability.

Q: Is flowise affected?

Yes, flowise is affected in releases prior to 3.0.6. Upgrade your dependency to 3.0.6 or later.

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

CVE-2025-59528 has a CVSS v3.1 base score of 10.0 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

Q: What CWE is associated with CVE-2025-59528?

CVE-2025-59528 is classified under CWE-94: Improper Control of Generation of Code ('Code Injection') (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.).

Q: How can I check npm dependencies for CVE-2025-59528?

Run the dependency tree command: 'npm ls flowise'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.

CRITICAL

Advisory Identifier: GHSA-3gcm-f6qx-ff7p

CVSS 10.0

CWE-94

Published 2025-09-15

Advisory Summary

CVE-2025-59528 is a CRITICAL (CVSS 10.0) remote code execution vulnerability (CWE-94: Improper Control of Generation of Code ('Code Injection')) affecting Flowise libraries in the npm ecosystem. The issue involves flowise has remote code execution vulnerability. Remediation is available by upgrading affected packages to version 3.0.6.

CVE-2025-59528 at a Glance

CVE Identifier CVE-2025-59528

GHSA Identifier GHSA-3gcm-f6qx-ff7p

Severity CRITICAL

CVSS v3.1 Base Score 10.0

CWE Classification CWE-94: Improper Control of Generation of Code ('Code Injection')

Affected Product Flowise

Package Ecosystem npm

Published Date 2025-09-15

Last Updated 2025-10-13

Security Impact

CVSS: 10.0

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H).

Attack Vector Network (AV:N)

Attack Complexity Low (AC:L)

Privileges Required None (PR:N)

User Interaction None (UI:N)

Scope Changed (S:C)

Confidentiality High (C:H)

Integrity High (I:H)

Availability High (A:H)

How to Fix CVE-2025-59528

To remediate this vulnerability, upgrade all affected Flowise dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

flowise fixed: 3.0.6

npm install flowise@3.0.6

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

npm ls flowise

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2025-59528, inspect your project dependencies using npm:

npm ls flowise

Analyze the terminal output to locate any version of Flowise in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.0.6), your application is affected.

Note: The npm ls flowise command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-94: Improper Control of Generation of Code ('Code Injection'), where 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. In Flowise, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Description ### Cause of the Vulnerability The `CustomMCP` node allows users to input configuration settings for connecting to an external MCP (Model Context Protocol) 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`. ### Vulnerability Flow 1. **User Input Received**: Input is provided via the API endpoint `/api/v1/node-load-method/customMCP` through the `mcpServerConfig` parameter. 2. **Variable Substitution**: The `substituteVariablesInString` function replaces template variables like `$vars.xxx`, but no security filtering is applied during this step. 3. **Dangerous Code Execution**: The `convertToValidJSONString` function executes the input using `Function('return ' + inputString)()`. If the `inputString` contains malicious code, it gets executed in the global Node.js context, allowing actions such as command execution and file system access. ## Taint Flow - **Taint 01: Route Registration** [`index.ts` (Line 5)](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/routes/node-load-methods/index.ts#L5) - **Taint 02: Controller** [`index.ts` (Line 57–78)](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/controllers/nodes/index.ts#L57-L78) - **Taint 03: Service** [`index.ts` (Line 91–94)](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/services/nodes/index.ts#L91-L94) - **Taint 04: CustomMCP Node Entry Point** [`CustomMCP.ts` (Line 132)](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L132) - **Taint 05: Variable Substitution** [`CustomMCP.ts` (Line 220)](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L220) - **Taint 06: Dangerous Constructor Execution** [`CustomMCP.ts` (Line 262–270)](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L262-L270) ## Proof of Concept (PoC) ```bash curl -X POST http://localhost:3000/api/v1/node-load-method/customMCP \ -H "Content-Type: application/json" \ -H "Authorization: Bearer tmY1fIjgqZ6-nWUuZ9G7VzDtlsOiSZlDZjFSxZrDd0Q" \ -d '{ "loadMethod": "listActions", "inputs": { "mcpServerConfig": "({x:(function(){const cp = process.mainModule.require(\"child_process\");cp.execSync(\"echo !!RCE-OK!! >/tmp/RCE.txt\");return 1;})()})" } }' ``` <img width="1907" height="958" alt="image" src="https://github.com/user-attachments/assets/78b50eb1-67af-4c8b-97ea-7e2c05426962" /> When executed, this creates a file `/tmp/RCE.txt` on the server, confirming command execution. ## Impact ### Complete System Takeover and Infrastructure Threat This vulnerability allows attackers to execute arbitrary JavaScript code on the Flowise server, leading to: - Full system compromise - File system access - Command execution - Sensitive data exfiltration As only an API token is required, this poses an extreme security risk to business continuity and customer data.

CVE-2025-59528 Affected Flowise Versions

1 component(s)

Fixed Versions:

3.0.6

Product / Package	Ecosystem	Affected Versions	Fixed Version
flowise npm/flowise	npm	≥ 3.0.5 < 3.0.6 All 1 versions 3.0.5	3.0.6

References

Flowise Source Repository REPOSITORY

https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/routes/node-load-methods/index.ts#L5

Flowise Source Repository REPOSITORY

https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/services/nodes/index.ts#L91-L94

Flowise Release RELEASE

https://github.com/FlowiseAI/Flowise/releases/tag/flowise%403.0.6

GitHub Advisory / Wiki ADVISORY

https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-3gcm-f6qx-ff7p

NVD — CVE-2025-59528 NVD

https://nvd.nist.gov/vuln/detail/CVE-2025-59528

Flowise Source Repository REPOSITORY

https://github.com/FlowiseAI/Flowise

Flowise Source Repository REPOSITORY

https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L132

Flowise Source Repository REPOSITORY

https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L220

Flowise Source Repository REPOSITORY

https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L262-L270

Flowise Source Repository REPOSITORY

https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/controllers/nodes/index.ts#L57-L78

Frequently Asked Questions

What is CVE-2025-59528?

CVE-2025-59528 is a security vulnerability in Flowise involving Flowise has Remote Code Execution vulnerability under CWE-94: Improper Control of Generation of Code ('Code Injection').

Which Flowise versions are affected?

Affected versions include releases prior to 3.0.6 across affected packages: flowise.

What version fixes CVE-2025-59528?

Upgrading to 3.0.6 (or the latest patched release for your respective branch) resolves the vulnerability.

Is flowise affected?

Yes, flowise is affected in releases prior to 3.0.6. Upgrade your dependency to 3.0.6 or later.

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

CVE-2025-59528 has a CVSS v3.1 base score of 10.0 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

What CWE is associated with CVE-2025-59528?

CVE-2025-59528 is classified under CWE-94: Improper Control of Generation of Code ('Code Injection') (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.).

How can I check npm dependencies for CVE-2025-59528?

Run the dependency tree command: 'npm ls flowise'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.

Machine-readable OSV JSON OSV v1.5 Schema

Normalized schema output

View Raw JSON

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-3gcm-f6qx-ff7p",
  "modified" : "2025-10-13T15:49:17Z",
  "published" : "2025-09-15T19:59:57Z",
  "aliases" : [ "CVE-2025-59528" ],
  "summary" : "Flowise has Remote Code Execution vulnerability",
  "details" : "## Description\n\n### Cause of the Vulnerability\n\nThe `CustomMCP` node allows users to input configuration settings for connecting to an external MCP (Model Context Protocol) 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.\n\nSpecifically, 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`.\n\n### Vulnerability Flow\n\n1. **User Input Received**: Input is provided via the API endpoint `/api/v1/node-load-method/customMCP` through the `mcpServerConfig` parameter.\n2. **Variable Substitution**: The `substituteVariablesInString` function replaces template variables like `$vars.xxx`, but no security filtering is applied during this step.\n3. **Dangerous Code Execution**: The `convertToValidJSONString` function executes the input using `Function('return ' + inputString)()`. If the `inputString` contains malicious code, it gets executed in the global Node.js context, allowing actions such as command execution and file system access.\n\n## Taint Flow\n\n- **Taint 01: Route Registration**  \n  [`index.ts` (Line 5)](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/routes/node-load-methods/index.ts#L5)\n\n- **Taint 02: Controller**  \n  [`index.ts` (Line 57–78)](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/controllers/nodes/index.ts#L57-L78)\n\n- **Taint 03: Service**  \n  [`index.ts` (Line 91–94)](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/services/nodes/index.ts#L91-L94)\n\n- **Taint 04: CustomMCP Node Entry Point**  \n  [`CustomMCP.ts` (Line 132)](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L132)\n\n- **Taint 05: Variable Substitution**  \n  [`CustomMCP.ts` (Line 220)](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L220)\n\n- **Taint 06: Dangerous Constructor Execution**  \n  [`CustomMCP.ts` (Line 262–270)](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L262-L270)\n\n## Proof of Concept (PoC)\n\n```bash\ncurl -X POST http://localhost:3000/api/v1/node-load-method/customMCP \\\n  -H \"Content-Type: application/json\" \\\n  -H \"Authorization: Bearer tmY1fIjgqZ6-nWUuZ9G7VzDtlsOiSZlDZjFSxZrDd0Q\" \\\n  -d '{\n    \"loadMethod\": \"listActions\",\n    \"inputs\": {\n      \"mcpServerConfig\": \"({x:(function(){const cp = process.mainModule.require(\\\"child_process\\\");cp.execSync(\\\"echo !!RCE-OK!! >/tmp/RCE.txt\\\");return 1;})()})\"\n    }\n  }'\n```\n<img width=\"1907\" height=\"958\" alt=\"image\" src=\"https://github.com/user-attachments/assets/78b50eb1-67af-4c8b-97ea-7e2c05426962\" />\n\nWhen executed, this creates a file `/tmp/RCE.txt` on the server, confirming command execution.\n\n## Impact\n\n### Complete System Takeover and Infrastructure Threat\n\nThis vulnerability allows attackers to execute arbitrary JavaScript code on the Flowise server, leading to:\n\n- Full system compromise\n- File system access\n- Command execution\n- Sensitive data exfiltration\n\nAs only an API token is required, this poses an extreme security risk to business continuity and customer data.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "flowise"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.0.5"
      }, {
        "fixed" : "3.0.6"
      } ]
    } ],
    "versions" : [ "3.0.5" ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-3gcm-f6qx-ff7p"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-59528"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/FlowiseAI/Flowise"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L132"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L220"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L262-L270"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/controllers/nodes/index.ts#L57-L78"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/routes/node-load-methods/index.ts#L5"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/services/nodes/index.ts#L91-L94"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FlowiseAI/Flowise/releases/tag/flowise%403.0.6"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-94" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-09-15T19:59:57Z",
    "nvd_published_at" : "2025-09-22T20:15:39Z"
  }
}

CVSS V3

10.0 CRITICAL

Attack Vector Network (AV:N)

Attack Complexity Low (AC:L)

Privileges Required None (PR:N)

User Interaction None (UI:N)

Scope Changed (S:C)

Confidentiality High (C:H)

Integrity High (I:H)

Availability High (A:H)

Vector String

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

Advisory Metadata

Source ID: GHSA-3gcm-f6qx-ff7p
Schema Version: 1.4.0
Published: 2025-09-15 19:59
Last Modified: 2025-10-13 15:49
Database Record File: advisories/github-reviewed/2025/09/GHSA-3gcm-f6qx-ff7p/GHSA-3gcm-f6qx-ff7p.json