Critical · published September 23, 2025
CVSS calls it critical at 10.0. It sits in the 99.7th percentile for exploit probability.
🚨 A sneaky flaw in Flowise version 3.0.5 lets attackers execute arbitrary code with just a crafted input — like handing a chef a recipe that includes a secret ingredient to sabotage the entire dish! 🔥 Think of it like a restaurant where the chef blindly follows any instruction given, even if it includes dangerous substitutions — one poorly thought-out order could ruin the entire meal. In this case, the input runs as if it’s part of the Node.js kitchen, giving the attacker access to all the dangerous tools! An attacker could leverage this vulnerability to execute malicious JavaScript code, potentially accessing sensitive files and executing commands on the server. Imagine them taking control of your kitchen operations, mixing ingredients you never wanted them to touch, and compromising the entire system! This is absolutely devastating if left unaddressed.
Think of it like a restaurant where the chef blindly follows any instruction given, even if it includes dangerous substitutions — one poorly thought-out order could ruin the entire meal. In this case, the input runs as if it’s part of the Node.js kitchen, giving the attacker access to all the dangerous tools! This vulnerability in Flowise allows for remote code execution due to unsafe parsing of the mcpServerConfig string within the CustomMCP node. The function convertToValidJSONString passes user input directly to the Function() constructor, executing it as JavaScript code with full Node.js privileges, exposing critical modules like child_process and fs.
An attacker could leverage this vulnerability to execute malicious JavaScript code, potentially accessing sensitive files and executing commands on the server. Imagine them taking control of your kitchen operations, mixing ingredients you never wanted them to touch, and compromising the entire system! This is absolutely devastating if left unaddressed. Immediately upgrade to Flowise version 3.0.6 to patch this critical vulnerability. Additionally, review and sanitize any user inputs to prevent similar issues in the future. Always validate and restrict what users can provide as configurations! You've got this! Follow these steps and secure your Flowise instance today! 🛡️
| Product | Versions | Fixed in |
|---|---|---|
| flowiseai/flowise | all versions | — |