Maxkb · Maxkb · CVE-2026-39420
**Name of the Vulnerable Software and Affected Versions**
MaxKB versions prior to 2.8.0
**Description**
An incomplete sandbox protection mechanism allows an authenticated user with tool execution privileges to escape the LD PRELOAD-based sandbox. The system restricts untrusted Python code execution via the 'Tool Debug API' by injecting `sandbox.so` through the `LD PRELOAD` environment variable to intercept sensitive C library functions such as `execve`, `socket`, and `open`. However, because the `/usr/bin/env` utility can be executed, an attacker can run the `env -i python` command. The `-i` flag clears all environment variables, including `LD PRELOAD`, which removes the `sandbox.so` hook. This allows the newly spawned Python process to execute natively, resulting in unrestricted Remote Code Execution (RCE) and network access.
**Recommendations**
Update to version 2.8.0.