Zero-Day Vulnerability

What is Zero-Day Vulnerability?

A zero-day vulnerability is one that is unknown to the software vendor and has no available patch. The name refers to the vendor having 'zero days' to fix it before it can be exploited. Zero-days are highly valuable to attackers because no defense exists yet. When a zero-day is discovered, organizations must rely on workarounds, WAF rules, or network-level mitigations until a patch is released. Continuous monitoring and rapid response capabilities are essential for managing zero-day risk.