CVE-2025-71336: Flowise remote code execution in Custom MCP feature

CVE-2025-71336 · Severity: critical · CVSS 9.8 · Published 2026-06-25

Flowise, an open-source tool for building LLM applications, contains a critical security flaw in its Custom MCP feature. This feature is intended to run system commands to manage local servers, but it lacks proper security boundaries and access controls. An attacker can exploit this to run unauthorized commands on the underlying server or container, potentially leading to a full system takeover and theft of sensitive data.

Technologies: flowise (npm). Vendors: npm.

Quick answers

Is CVE-2025-71336 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2025-71336 being exploited in the wild.
How severe is CVE-2025-71336?
Critical severity, with a CVSS score of 9.8, published 25 June 2026.
Which products and versions are affected?
flowise (npm) >= 2.2.7-patch.1, < 3.0.6, SEMVER:introduced=2.2.7-patch.1,fixed=3.0.6.
Is there a fix for CVE-2025-71336?
Yes. flowise (npm): upgrade to 3.0.6 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2025-71336 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2025-71336?
Check whether you run flowise (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • flowise (npm): upgrade to 3.0.6 or later
    npm install flowise@3.0.6

Technical details

A remote code execution (RCE) vulnerability exists in Flowise versions prior to 3.0.6 within the Custom Model Context Protocol (MCP) feature. The root cause is a lack of sandboxing and insufficient access controls on the `/api/v1/node-load-method/customMCP` endpoint. Because Flowise often runs without authentication by default and lacks role-based access control (RBAC), an attacker can send a crafted JSON payload containing OS commands with the header 'x-request-from: internal' to achieve arbitrary command execution. This allows for complete compromise of the host server or container. The issue is addressed in version 3.0.6.

Affected products

  • FlowiseAI Flowise < 3.0.6 (including 2.2.7-patch.1 and earlier)

Identifiers

  • CVE-2025-71336
  • GHSA-6933-jpx5-q87q

Timeline

  • 2025-09-13: advisory: GitHub Security Advisory published
  • 2026-06-25: disclosed: NVD publication and CVE assignment

References

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