CVE-2026-56275

Flowise before 3.1.0 contains a server-side request forgery vulnerability in the Execute Flow node that allows attackers to bypass security validation by providing intranet addresses through the base URL field. Attackers can initiate HTTP requests to internal network addresses, access cloud metadata, and enumerate internal services by exploiting the missing secureFetch verification in httpSecurity.ts.

Flowise before 3.1.0 contains a server-side request forgery vulnerability in the Execute Flow node that allows attackers to bypass security validation by providing intranet addresses through the base URL field. Attackers can initiate HTTP requests to internal network addresses, access cloud metadata, and enumerate internal services by exploiting the missing secureFetch verification in httpSecurity.ts.

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

<img width="1280" height="860" alt="9a52a74e6fe2fd78e4962d1d68057fc2" src="https://github.com/user-attachments/assets/20df0006-9129-4886-8928-16d19a617c23" />

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:

<img width="1432" height="172" alt="f45c757fec408e13739db068252ff21b" src="https://github.com/user-attachments/assets/d3dfe0f5-83ec-4c79-ab32-754382a68d5f" />

And there is an echo:

<img width="1280" height="666" alt="fa0caf0deb306cfeeea8fdf8941a287e" src="https://github.com/user-attachments/assets/55a94d25-120b-4e9c-9517-46c2fc2b667f" />

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.

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-9hrv-gvrv-6gf2. This link is maintained to preserve external references.

Original Description

Flowise before 3.1.0 contains a server-side request forgery vulnerability in the Execute Flow node that allows attackers to bypass security validation by providing intranet addresses through the base URL field. Attackers can initiate HTTP requests to internal network addresses, access cloud metadata, and enumerate internal services by exploiting the missing secureFetch verification in httpSecurity.ts.

Flowise before 3.1.0 contains a server-side request forgery vulnerability in the Execute Flow node that allows attackers to bypass security validation by providing intranet addresses through the base URL field. Attackers can initiate HTTP requests to internal network addresses, access cloud metadata, and enumerate internal services by exploiting the missing secureFetch verification in httpSecurity.ts.

Flowise before 3.1.0 contains a server-side request forgery vulnerability in the Execute Flow node that allows attackers to bypass security validation by providing intranet addresses through the base URL field. Attackers can initiate HTTP requests to internal network addresses, access cloud metadata, and enumerate internal services by exploiting the missing secureFetch verification in httpSecurity.ts.

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

<img width="1280" height="860" alt="9a52a74e6fe2fd78e4962d1d68057fc2" src="https://github.com/user-attachments/assets/20df0006-9129-4886-8928-16d19a617c23" />

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:

<img width="1432" height="172" alt="f45c757fec408e13739db068252ff21b" src="https://github.com/user-attachments/assets/d3dfe0f5-83ec-4c79-ab32-754382a68d5f" />

And there is an echo:

<img width="1280" height="666" alt="fa0caf0deb306cfeeea8fdf8941a287e" src="https://github.com/user-attachments/assets/55a94d25-120b-4e9c-9517-46c2fc2b667f" />

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.

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-9hrv-gvrv-6gf2. This link is maintained to preserve external references.

Original Description

Flowise before 3.1.0 contains a server-side request forgery vulnerability in the Execute Flow node that allows attackers to bypass security validation by providing intranet addresses through the base URL field. Attackers can initiate HTTP requests to internal network addresses, access cloud metadata, and enumerate internal services by exploiting the missing secureFetch verification in httpSecurity.ts.