PraisonAI SandlockSandbox falls back to unrestricted subprocess execution when Landlock is unavailable

PraisonAI is a multi-agent teams system. From version 4.5.110 to before version 4.6.61, praisonai.sandbox.SandlockSandbox is documented and implemented as the kernel-enforced sandbox backend for untrusted code. Its SandboxConfig.native() path lets callers configure allowed filesystem paths and network=False. On systems where the optional sandlock module imports but reports that Landlock is unavailable, SandlockSandbox.execute() and run_command() do not fail closed. They silently fall back to SubprocessSandbox(self.config). That fallback keeps the same high-level native policy object but does not enforce the native filesystem or network boundary during code execution. A sandboxed payload can read files outside the configured allowed path and open network connections despite network=False. This issue has been patched in version 4.6.61.