CVE-2025-26319
📋 TL;DR
FlowiseAI Flowise v2.2.6 contains an arbitrary file upload vulnerability in the /api/v1/attachments endpoint that allows attackers to upload malicious files without proper validation. This affects all users running vulnerable versions of FlowiseAI Flowise. Successful exploitation could lead to remote code execution or server compromise.
💻 Affected Systems
- FlowiseAI Flowise
📦 What is this software?
Flowise by Flowiseai
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with remote code execution, data exfiltration, and lateral movement within the network.
Likely Case
Webshell deployment leading to persistent backdoor access, file system manipulation, and potential credential theft.
If Mitigated
Limited impact with proper file validation and access controls preventing malicious uploads.
🎯 Exploit Status
Public proof-of-concept available on GitHub demonstrates exploitation. Simple HTTP requests can trigger the vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v2.2.7 or later
Vendor Advisory: https://github.com/FlowiseAI/Flowise/security/advisories
Restart Required: Yes
Instructions:
1. Backup your Flowise configuration and data. 2. Update to Flowise v2.2.7 or later using npm update or package manager. 3. Restart the Flowise service. 4. Verify the fix by testing the attachments endpoint.
🔧 Temporary Workarounds
API Endpoint Restriction
allBlock or restrict access to the vulnerable /api/v1/attachments endpoint using web application firewall or reverse proxy rules.
# Example nginx location block
location /api/v1/attachments { deny all; }
File Upload Validation
allImplement server-side file type validation and size restrictions for uploads.
# Implement file validation middleware
# Check file extensions, MIME types, and size limits
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Flowise instances from critical systems.
- Deploy web application firewall with file upload protection rules and monitor for suspicious upload attempts.
🔍 How to Verify
Check if Vulnerable:
Test if you can upload arbitrary files (e.g., .php, .jsp, .exe) to /api/v1/attachments endpoint without proper validation.Check Version:
npm list flowise or check package.json for Flowise versionVerify Fix Applied:
After patching, attempt to upload malicious files to the attachments endpoint - should be rejected with proper error messages.📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads to /api/v1/attachments
- Uploads of executable file types
- Large number of upload requests
Network Indicators:
- HTTP POST requests to /api/v1/attachments with suspicious file extensions
- Unusual outbound connections from Flowise server
SIEM Query:
source="flowise.logs" AND (uri_path="/api/v1/attachments" AND file_extension IN ("php", "jsp", "exe", "sh"))