Exploit Code Published for Critical Flowise RCE Vulnerability
Vulnerability: Critical RCE flaw in Flowise (CVE-2026-40933) allows attackers to execute arbitrary commands via malicious chatflow imports.
Deep Analysis and Expert Commentary
The vulnerability exploits a systemic command injection weakness in Anthropic MCP's stdio serialization, propagating through Flowise's Custom MCP Tool configuration. Attackers craft a malicious chatflow, export it as JSON, and lure victims into importing it. Upon rendering, the chatflow triggers command execution via the MCP server enumeration process, often with root privileges in containers. The attack path requires either compromised user credentials or insider access, but the payload's simplicity increases exploit likelihood. Mitigations include upgrading to Flowise 3.1.0+, disabling stdio MCP in self-hosted instances, and restricting chatflow imports to trusted sources. Organizations should audit connected services (databases, APIs) for lateral movement signs, as the flaw exposes all platform-stored credentials.
Action Items
- Upgrade Flowise to version 3.1.0 or later immediately.
- Disable stdio MCP transport in self-hosted deployments if unused.
- Implement strict controls on chatflow imports and user permissions.
- Audit connected services for anomalous activity post-exploitation.
Original Article Brief Intro
SecurityWeek · 2026-05-30 · Vulnerability: Critical RCE flaw in Flowise (CVE-2026-40933) allows attackers to execute arbitrary commands via malicious chatflow imports.
Related Terms and Notes
CVE IDs
- CVE-2026-40933 — Critical RCE vulnerability in Flowise via unsafe stdio command serialization in Anthropic MCP (CVSS 9.9).
Techniques / TTPs
- Flowise RCE
- RCE
Context Notes
- AI Security
- AI Workflow Vulnerabilities
- Anthropic MCP — Protocol used in AI ecosystems for tool interoperability, vulnerable to command injection in stdio transport.
- Command Injection
- Flowise
- Remote Code Execution