CVE-2026-91931: Flowiseai Flowise

High severity, CVSS 8.5. EPSS: 0.7% chance of exploitation in the next 30 days.

Flowise before 3.1.4 contains a remote code execution vulnerability in the Custom MCP node that allows authenticated attackers to execute arbitrary code by supplying npx package names in the mcpServerConfig parameter. Attackers can invoke npx with attacker-controlled npm packages to execute code on the Flowise server.

Affected products

• Flowiseai Flowise: before 3.1.4 (fixed in 3.1.4)

Published 2026-09-15. Last modified 2026-09-23.