Gate every agent deployment against the Lethal Trifecta — remove one leg and the exfiltration risk collapses

Airia·high signal

Prompt injection drove most agentic-AI security failures in production in 2026, and the cleanest deployment heuristic is the 'Lethal Trifecta': an agent is dangerous only when it simultaneously has access to private data, exposure to untrusted tokens, and an exfiltration vector. Before shipping, audit each agent for all three and architect to break at least one leg — e.g., strip the outbound channel, sandbox untrusted input, or scope away the sensitive data — rather than hoping a single guardrail catches semantic manipulation that WAFs and input validation cannot. Defense-in-depth with overlapping layers and tool allow-lists backs it up, but the trifecta check is the first gate.