Agent memory poisoning turns persistence into a new security risk

AI agents are becoming more useful because they can remember. That same persistence creates a new security problem: if attackers can poison memory, they may influence future actions long after the original interaction is over.

This changes the threat model for agentic systems. Prompt injection is no longer just about one bad response; it can become a stored instruction, corrupted preference, or hidden context that shapes later work. Memory turns the agent from a stateless tool into something closer to a user account with history.

For developers, the fix requires more than better prompts. Agent memory needs permissions, provenance, expiry, review controls, and ways to separate trusted facts from untrusted text. Persistent AI needs persistent security.