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 <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.

CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

Severity from

GitHub (reviewed advisory)

Weakness

CWE-918

Also known as

CVE-2026-56275

• github.com/FlowiseAI/Flowise/security/advisories/GHSA-9hrv-gvrv-6gf2
• nvd.nist.gov/vuln/detail/CVE-2026-56275
• github.com/FlowiseAI/Flowise
• www.vulncheck.com/advisories/flowise-server-side-request-forgery-via-execute-flow-base-url