Three Security Issues Specific to Multi-Agent AI Systems (OWASP Agentic AI Top 10)

When you move from a single agent to multiple agents that call each other, you get a new category of security problems that single-agent systems don't have. Each agent-to-agent interface is a trust boundary — and most multi-agent frameworks leave those boundaries implicit. The OWASP Agentic AI Top 10 (2026) documents the most common vulnerability classes in agentic systems. This post covers three of them with concrete examples and the code patterns that address them. 1. Prompt Injection via Tool