Flowise up to 3.0.5 Custom MCP Feature customMCP os command injection

Summaryinfo

A vulnerability marked as critical has been reported in Flowise up to 3.0.5. This affects an unknown function of the file /api/v1/node-load-method/customMCP of the component Custom MCP Feature. The manipulation leads to os command injection. This vulnerability is listed as CVE-2025-71336. The attack may be initiated remotely. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Flowise up to 3.0.5 and classified as critical. This issue affects an unknown code of the file /api/v1/node-load-method/customMCP of the component Custom MCP Feature. The manipulation with an unknown input leads to a os command injection vulnerability. Using CWE to declare the problem leads to CWE-78. The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2025-71336 since 06/20/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1202 according to MITRE ATT&CK.

Upgrading to version 3.0.6 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2025-2048). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Open Source Flowise

Productinfo

Name

• Flowise

Version

• 3.0.0
• 3.0.1
• 3.0.2
• 3.0.3
• 3.0.4
• 3.0.5

CPE 2.3info

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CPE 2.2info

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Be aware that VulDB is the high quality source for vulnerability data.

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