Vulnerability · Published Jun 25, 2026 · Assigned by VulnCheck
CVE-2025-71336Flowise - Unsandboxed Remote Code Execution via Custom MCP
Critical 9.8
In plain English
A critical-severity OS command injection in Flowise from Flowise. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 1.1% (higher than 67% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | flowise | 3.0.6 | GHSA-6933-jpx5-q87q |
Affected products (as reported)
Weakness: CWE-78 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References
- GitHub Security Advisory (GHSA-6933-jpx5-q87q) vendor-advisory
- VulnCheck Advisory: Flowise - Unsandboxed Remote Code Execution via Custom MCP third-party-advisory