Flowise before 3.1.4 Remote Code Execution via Custom MCP npx (CVE-2026-91931) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-91931

Flowise before 3.1.4 Remote Code Execution via Custom MCP npx

Answer in brief

CVE-2026-91931 records a Unknown severity vulnerability in Flowise before 3.1.4 Remote Code Execution via Custom MCP npx. The current sources do not mark it as known exploited. The current feed maps FlowiseAI/Flowise (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 15, 2026Updated Sep 15, 2026Source checked Sep 15, 2026First seen by HOL Sep 15, 2026Material review Sep 15, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps FlowiseAI/Flowise (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
FlowiseAI/Flowisegeneric	>=0 <3.1.4	3.1.4

Recommended response

Check inventory. Check lockfiles and deployed manifests for FlowiseAI/Flowise.
Review the reported fix. Update FlowiseAI/Flowise to 3.1.4 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 15, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.