Vulnerability · Published Sep 15, 2026 · Assigned by VulnCheck
CVE-2026-91931Flowise before 3.1.4 Remote Code Execution via Custom MCP npx
High 8.5
In plain English
A high-severity OS command injection in Flowise from FlowiseAI. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 52% of all known vulnerabilities).
Severity (CVSS 3.1)8.5High
Exploit odds (30 days)0.7%top 47.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
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 (as reported)
Weakness: CWE-78 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
References
- GitHub Security Advisory (GHSA-vcwp-f9rq-3887) vendor-advisory
- VulnCheck Advisory: Flowise before 3.1.4 Remote Code Execution via Custom MCP npx third-party-advisory