Sandbox Escape Vulnerability in MaxKB Open-Source AI Assistant

CVE-2026-39421

What is CVE-2026-39421?

The MaxKB open-source AI assistant for enterprise has a critical vulnerability in the ToolExecutor component, allowing authenticated attackers with workspace privileges to execute raw system calls. By exploiting the Python ctypes library, attackers can bypass security measures implemented through the LD_PRELOAD-based sandbox.so module, leading to arbitrary code execution. This vulnerability enables full network exfiltration and potential container compromise, as critical standard system functions such as execve and connect can be intercepted. Although the library attempts to restrict executable memory allocations within sandboxed Python processes, the pkey_mprotect function remains unblocked. This issue has been addressed in version 2.8.0.

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