Vulnerability Report

CVE-2025-71336

RCE

Title: Unsandboxed RCE via Custom MCP Feature

RCE

Proof Of Concept

No public PoC currently indexed for CVE-2025-71336.

CWE Category CWE-78

Published Date Jun 25, 2026

Modified Date Jul 01, 2026

Exploit Status Not Found

Score 9.3 CVSS v4.0

Exploit Probability (EPSS)

1.56%

Vulnerability Summary

CVE-2025-71336: Flowise before 3.0.6 (affected versions 2.2.7-patch.1 and earlier) contains an unsandboxed remote code execution vulnerability in the Custom MCP feature, which is designed to execute OS commands such as launching local MCP servers. Because Flowise's authentication and authorization model is minimal and lacks role-based access control, and the default installation runs without authentication unless FLOWISE_USERNAME and FLOWISE_PASSWORD are set, an attacker can send a crafted JSON payload with the header 'x-request-from: internal' to the /api/v1/node-load-method/customMCP endpoint to execute arbitrary OS commands, resulting in complete compromise of the platform container or server.

Impacted Vendors

flowiseai 1

Reference Links

https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-6933-jpx5-q87q https://www.vulncheck.com/advisories/flowise-unsandboxed-remote-code-execution-via-custom-mcp

CVSS v4.0

Source Entity [email protected]

Severity CRITICAL

9.3

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

N/A

RAW VECTOR

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1