CVE-2026-58057

The record

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.

Affected packages

Related vulnerabilities

• CVE-2026-86472 fast-uri is a dependency-free RFC 3986 URI parser for Node.js, used by Fastify and ajv. CWE-178
• CVE-2026-87876 Two case-insensitive comparisons on request-derived usernames outside the main… CWE-178
• CVE-2026-84428 fastify versions before 5.12.2 implement the case-insensitive nature of HTTP header names… CWE-178
• CVE-2026-84303 gRPC-Go is the Go language implementation of gRPC. CWE-178
• CVE-2026-83612 xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and… CWE-178
• CVE-2026-73270 Improper Handling of Case Sensitivity vulnerability in Erlang/OTP inets httpd allows a… CWE-178
• CVE-2026-82726 Permissive Regular Expression vulnerability in ash-project ash_phoenix lets a remote… CWE-178
• CVE-2026-78959 Improper handling of case sensitivity in FileSystem in Google Chrome prior to… CWE-178