High severity · published Sep 15, 2026
CVE-2026-91931
Flowise before 3.1.4 Remote Code Execution via Custom MCP npx
8.5
CVSS
0.7%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
High
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 52% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FL
Flowise · FlowiseAI
before 3.1.4; before 3.1.4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-91931
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-91931
github.com
https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-vcwp-f9rq-3887
www.vulncheck.com
https://www.vulncheck.com/advisories/flowise-before-3.1.4-remote-code-execution-via-custom-mcp-npx
More from Flowise
10.0
CVE-2026-70478
Flowise: Unauthenticated OAuth2 token refresh endpoint returns access tokens — enables token theft for any connected service
10.0
CVE-2025-59528
Flowise has Remote Code Execution vulnerability
9.9
CVE-2026-73602
Flowise before 3.1.3 Sandbox Escape to RCE
9.9
CVE-2026-67622
Flowise 3.1.4 IDOR in OpenAI Assistants Integration
9.9
CVE-2026-56274
Flowise - Remote Code Execution via MCP Security Bypass in validateCommandFlags and validateArgsForLocalFileAccess