CVE-2026-33057 Mesop Affected by Unauthenticated Remote Code Execution via Test Suite Route /exec-py
Unauthenticated attackers can execute arbitrary Python code via the /exec-py endpoint in Mesop, leading to full host compromise.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-33057?
CVE-2026-33057 is a critical code injection vulnerability in mesop-dev mesop, published on 20 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Mesop is a Python-based UI framework that allows users to build web applications. In versions 1.2.2 and below, 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. 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...). This issue has been fixed in version 1.2.3.
Weakness: CWE-94
Which versions are affected by CVE-2026-33057?
3 open source packages ship an affected version, including mesop. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
mesop PyPI | All versions | 1.2.3 |
mesop PyPI | All versions | 1.2.3 |
mesop PyPI | All versions | 1.2.3 |
Products include Mesop-Dev Mesop.
How do I fix CVE-2026-33057?
Upgrade mesop to 1.2.3 or later.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-33057 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33057 exists.
Public exploit code: 1 Nuclei template and 1 proofs of concept on GitHub.
Other vulnerabilities in mesop-dev mesop
Sources
Also known as GHSA-gjgx-rvqr-6w6v, PYSEC-2026-412.