CVE-2026-56275: Flowise Execute Flow function has an SSRF vulnerability

Summary

The attacker provides an intranet address through the base url field configured in the Execute Flow node → Bypass checkDenyList / resolveAndValidate in httpSecurity.ts (not called) → Causes the server to initiate an HTTP request to any internal network address, read cloud metadata, or detect internal network services

Details

Then initiate the call:

POST /api/v1/prediction/d6739838-d3b3-43d9-86ff-911a3d757a7e HTTP/1.1
Host: 127.0.0.1:3000
Content-Type: application/json
Authorization: Bearer apikey
Content-Length: 17

{"question": "1"}

Server received a request:

And there is an echo:

Fix: Call secureFetch for verification

Impact

This is a Server-Side Request Forgery (SSRF) vulnerability that may lead to the following risks:

• Explore Internal Web Applications
• Access sensitive management interfaces
• Leak internal configuration, credentials, or confidential information

This vulnerability significantly increases the risk of internal service enumeration and potential lateral movement in enterprise environments.