GHSA-2763-cj5r-c79m: PraisonAI Vulnerable to OS Command Injection

PraisonAI has a critical vulnerability where the `execute_command` function and workflow shell execution pass user-controlled input directly to `subprocess.run()` with `shell=True`, allowing attackers to inject arbitrary shell commands through YAML workflow files, agent configurations, and LLM-generated tool calls by exploiting shell metacharacters like semicolons and pipes.