CVE-2026-58057

Flowise before 3.1.3 validates Custom MCP stdio environment variables against a denylist using a case-sensitive comparison, so on Windows, where environment names are case-insensitive, supplying 'node_options' bypasses the NODE_OPTIONS denylist entry. An authenticated user who can configure a Custom MCP node can thereby inject NODE_OPTIONS --require and execute arbitrary code in the Flowise server context.

CVSS v3 5.0 MEDIUM

5.0^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.6 / Impact : 3.4

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://github.com/FlowiseAI/Flowise/pull/6471	Issue Tracking Patch
https://github.com/bikini/exploitarium/tree/main/flowise-mcp-env-case-bypass-poc	Exploit Third Party Advisory
https://www.vulncheck.com/advisories/flowise-custom-mcp-environment-variable-denylist-bypass-via-case-sensitivity	Exploit Patch Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:flowiseai:flowise:*:*:*:*:*:*:*:*

History

25 Oct 2026, 17:10

Type	Values Removed	Values Added
Summary		(es) Flowise antes de la versión 3.1.3 valida las variables de entorno stdio de Custom MCP contra una lista de denegación utilizando una comparación que distingue entre mayúsculas y minúsculas, por lo que en Windows, donde los nombres de las variables de entorno no distinguen entre mayúsculas y minúsculas, proporcionar ’node_options’ elude la entrada NODE_OPTIONS de la lista de denegación. Un usuario autenticado que puede configurar un nodo Custom MCP puede así inyectar NODE_OPTIONS --require y ejecutar código arbitrario en el contexto del servidor Flowise.

Information

Published : 2026-06-28 02:16

Updated : 2026-10-25 17:10

NVD link : CVE-2026-58057

Mitre link : CVE-2026-58057

CVE.ORG link : CVE-2026-58057

JSON object : View

Products Affected

flowiseai

flowise

CWE

CWE-178

Improper Handling of Case Sensitivity

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