ZDI-CAN-29475: ZDI-26-305: (0Day) OpenAI Codex Sandbox Escape Vulnerability

Published Apr 28, 2026

Updated

This vulnerability allows remote attackers to bypass the sandbox on affected installations of OpenAI Codex. User interaction is required to exploit this vulnerability in that the target must use Codex to process a repository containing malicious JavaScript. The ZDI has assigned a CVSS rating of 8.6.

Affected Software

1 affected component

OpenAI OpenAI Codex

Event History

Apr 28, 2026

Advisory Published

via ZDI·05:00 AM

Data Sourced

via ZDI·05:00 AM

Description

Frequently Asked Questions

What is the severity of ZDI-CAN-29475?

The severity of ZDI-CAN-29475 is considered high due to its ability to allow remote code execution via sandbox escape.

How do I fix ZDI-CAN-29475?

To fix ZDI-CAN-29475, ensure that you update OpenAI Codex to the latest patched version provided by OpenAI.

What software is affected by ZDI-CAN-29475?

ZDI-CAN-29475 affects all installations of OpenAI Codex.

What type of vulnerability is ZDI-CAN-29475?

ZDI-CAN-29475 is a sandbox escape vulnerability, allowing unauthorized access outside of a secure coding environment.

What are the potential consequences of exploiting ZDI-CAN-29475?

Exploiting ZDI-CAN-29475 can lead to unauthorized remote code execution, compromising the security of the affected systems.