Agentic testing is a form of security testing where an autonomous system does more than scan for suspicious patterns: it forms hypotheses about a flaw and then actively verifies them with checks such as test payloads, repeated requests, or browser interactions. The goal is to move from “this might be vulnerable” to “this behaves like a real vulnerability.”
In cyber security, this matters because many tools generate noisy results that still need manual proof. Agentic testing can reduce that gap by combining search, decision-making, and validation at scale. It is especially useful for web flaws like cross-site scripting, where a system can hunt for untrusted input that reaches an executable sink and then confirm whether script execution actually occurs. Defenders use this approach to prioritize fixes, while attackers may use similar automation to explore larger attack surfaces more quickly. It works best alongside strong controls such as output encoding, Content Security Policy, and Trusted Types.