CVE-2026-58057 MEDIUM

CVE-2026-58057: Flowise - Custom MCP Environment Variable Denylist Bypass via Case Sensitivity

Vendor Flowise
Product Flowise
Weakness CWE-178
Published June 28, 2026
Last update June 29, 2026
View on NVD All CVEs

CVSS base score

5.0/10
Attack vector Network
Attack complexity High
Privileges required Low
User interaction None
Confidentiality Low
Integrity Low

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

June 28, 2026 CVE published
June 29, 2026 Record updated