What is CVE-2026-91931?

CVE-2026-91931 is a high-severity vulnerability in Flowiseai Flowise, classified under OS Command Injection. CVSS score: 8.5/10. Published 2026-09-15.

How severe is CVE-2026-91931?

High severity. CVSS v3 base score is 8.5 out of 10.

RCE in Flowiseai Flowise

CVE-2026-91931

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.

Vulnerability class: Command Injection (OS Command Injection)

CVSS v3 metric

CVSS v3 base score 8.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H.

Affected products

Flowiseai Flowise

Weakness classification (CWE)

CWE-78 — OS Command Injection

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-91931?: CVE-2026-91931 is a high-severity vulnerability in Flowiseai Flowise, classified under OS Command Injection. CVSS score: 8.5/10. Published 2026-09-15.
How severe is CVE-2026-91931?: High severity. CVSS v3 base score is 8.5 out of 10.