PraisonAI is a multi-agent teams system. Prior to version 4.6.40 of PraisonAI, corresponding to version 1.6.40 of praisonaiagents, "execute_code()" in "praisonaiagents/tools/python_tools.py" (v1.6.37, subprocess sandbox mode) can be fully bypassed using "print.__self__" to retrieve the real Python "builtins" module, from which "__import__" can be extracted via "vars()" and runtime string construction. This achieves arbitrary OS command execution on the host, completely defeating the sandbox. This is a novel bypass that survives all patches for CVE-2026-39888 (frame traversal), CVE-2026-34938 (str subclass), and CVE-2026-40158 ("type.__getattribute__" trampoline). PraisonAI version 4.6.40 and praisonaiagents version 1.6.40 contain an updated fix.