---
title: "CVE-2025-59528: Flowise has Remote Code Execution vulnerability"
url: https://erroneo.us/security/cve/CVE-2025-59528/
description: "CVE-2025-59528 (flowise (npm)): Flowise is a drag & drop user interface to build a customized large language model flow. In version 3.0.5, Flowise is…"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-09-22
date_modified: 2025-09-22
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-59528"
kev: false
cvss: 10
epss: 0.86218
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2025-59528: Flowise has Remote Code Execution vulnerability

**Signal:** High exploit likelihood. EPSS ranks it in the top 5% of all CVEs for likely exploitation in the next 30 days. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 86.2% , percentile 99.7: FIRST’s model estimates a 86.2% chance of exploitation activity in the next 30 days, higher than 99.7% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes flowise (npm) = 3.0.5, fixed in 3.0.6 . Check your lockfile, including transitive dependencies.

## What it 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 childprocess and fs. This issue has been patched in version 3.0.6.

## Affected packages

- npm `flowise` = 3.0.5 → fixed: 3.0.6

## Affected products (CVE record)

- FlowiseAI Flowise: = 3.0.5

## Severity

- GitHub_M CVSS 3.1: 10 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`
- GitHub CVSS 3.1: 10.0 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 86.22% probability of exploitation activity in the next 30 days; percentile 99.7.

## Sources

- [GitHub Advisory GHSA-3gcm-f6qx-ff7p](https://github.com/advisories/GHSA-3gcm-f6qx-ff7p)
- [CVE.org record CVE-2025-59528](https://www.cve.org/CVERecord?id=CVE-2025-59528)
- [NVD entry CVE-2025-59528](https://nvd.nist.gov/vuln/detail/CVE-2025-59528)
- [github.com](https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-3gcm-f6qx-ff7p)
- [github.com](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L132)
- [github.com](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L220)
- [github.com](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/components/nodes/tools/MCP/CustomMCP/CustomMCP.ts#L262-L270)
- [github.com](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/controllers/nodes/index.ts#L57-L78)
- [github.com](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/routes/node-load-methods/index.ts#L5)
- [github.com](https://github.com/FlowiseAI/Flowise/blob/5930f1119c655bcf8d2200ae827a1f5b9fec81d0/packages/server/src/services/nodes/index.ts#L91-L94)
- [github.com](https://github.com/FlowiseAI/Flowise/releases/tag/flowise%403.0.6)

---
Source page: https://erroneo.us/security/cve/CVE-2025-59528/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt