Attack Chain

1. The attacker sends an HTTP GET request to /api/v1/auto_login to obtain an access token.
2. The server responds with a JSON object containing an access_token.
3. The attacker crafts a malicious HTTP POST request to /api/v1/validate/code endpoint.
4. The attacker sets the Authorization header with a Bearare {access_token} string.
5. The request body contains a JSON object with a code parameter. This code parameter contains a Python script that leverages the subprocess module to execute arbitrary commands.
6. The Python script within the code parameter utilizes __import__('subprocess').run('%s', shell=True, capture_output=True, text=True) to execute the attacker-controlled command.
7. The server executes the attacker-supplied command with root privileges.
8. The output of the command is returned to the attacker via the API response, confirming code execution.

Impact

Successful exploitation of this vulnerability allows an unauthenticated attacker to execute arbitrary code with root privileges on the Langflow server. This can lead to complete system compromise, data theft, denial of service, or further lateral movement within the network. Given the nature of Langflow as a low-code framework designed for building flows with Large Language Models, such a compromise could lead to the exposure of sensitive LLM configurations, API keys, and data used within these flows.

Recommendation

• Apply the patch or upgrade to a secure version of Langflow to remediate CVE-2026-0770.
• Deploy the Sigma rule Detect Langflow RCE via Validate Endpoint to detect exploitation attempts in web server logs.
• Monitor network traffic for unusual POST requests to the /api/v1/validate/code endpoint containing shell metacharacters in the code parameter.