CVE-2026-27966: Langflow [PoC]

Overview

A critical security vulnerability has been identified in Langflow, a platform for building AI agents and workflows. This flaw allows an attacker to execute arbitrary commands on the server hosting the application, potentially leading to a complete system compromise.

Vulnerability Details

In Langflow versions before 1.8.0, a specific component called the “CSV Agent” node was configured with an unsafe setting. This setting automatically enabled a powerful Python execution tool without proper safeguards. Normally, such a tool would be restricted, but this misconfiguration left it fully exposed.

An attacker can exploit this by crafting a malicious input, often through a technique called “prompt injection,” into an AI agent built with the vulnerable node. This input tricks the system into passing commands directly to the underlying server. As a result, the attacker can run any Python code or operating system command with the same permissions as the Langflow application, leading to Remote Code Execution (RCE).

Impact

The impact of this vulnerability is severe (CVSS Score: 9.8/10, CRITICAL). Successful exploitation grants an attacker the ability to:

• Steal, modify, or delete sensitive data from the server.
• Install malware or ransomware.
• Use the compromised server to attack other internal systems.
• Disrupt operations by shutting down services.

Any Langflow instance using the CSV Agent node from a version prior to 1.8.0 is at risk if its agents are exposed to untrusted user input.

Remediation and Mitigation

Immediate action is required to secure affected systems.

Primary Fix: Upgrade The definitive solution is to upgrade Langflow to version 1.8.0 or later. This version removes the dangerous hardcoded setting, properly securing the CSV Agent node.

1. Check your current Langflow version.
2. Follow the official upgrade procedures to update to version 1.8.0 or the latest stable release.

Temporary Mitigation (If Immediate Upgrade is Not Possible) If you cannot upgrade immediately, take these steps to reduce risk:

1. Disable or Remove the CSV Agent Node: Review all deployed workflows and remove any instances of the CSV Agent node. Replace its functionality with alternative, secure nodes if necessary.
2. Restrict Access: Ensure Langflow’s interface and API are not exposed to the public internet. Place the application behind strict network firewalls and enforce strong authentication.
3. Audit Logs: Closely monitor application and system logs for any unusual command execution or unexpected process activity.

After applying mitigations, plan for a permanent upgrade as soon as possible.