As AI agents become more autonomous, they increasingly rely on persistent memory—vector stores, session context, and episodic memory—to operate across multiple tasks. But this memory introduces a critical new attack surface. If an adversary can inject malicious instructions into an agent's memory, those instructions can lie dormant until retrieved, hijacking the agent's behavior long after the initial interaction. This is known as Memory Poisoning , classified by OWASP as ASI06 in the LLM Applications Top 10 . In this tutorial, I'll show you how to protect your LangChain agents against memory poisoning using OWASP Agent Memory Guard , an open-source runtime defense layer. What is OWASP Agent Memory Guard? OWASP Agent Memory Guard is an official OWASP incubator project. It acts as a middleware layer that intercepts every read and write operation to your agent's memory, screening for: Prompt Injection Attempts: Detecting malicious instructions before they are stored.…