CVE-2025-71336

CRITICAL 9.8

Flowise - Unsandboxed Remote Code Execution via Custom MCP

CVSS Score

9.8

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-78
Vendor	flowise
Product	flowise
Published	Jun 25, 2026

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CVSS v3 Breakdown

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

Flowise / Flowise

0 < 3.0.6

References

NVD ↗ CVE.org ↗ EPSS Data ↗

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

Credits

🔍 assaf-levkovich-jf