What does the term 'zero-day vulnerability' refer to?

The term 'zero-day vulnerability' refers to a security flaw in software or hardware that is unknown to the vendor and has not yet been patched. This type of vulnerability is particularly dangerous because it can be actively exploited by attackers before the organization or developer is even aware of its existence. When a zero-day vulnerability is discovered and exploited, it poses significant risks to affected systems since there are no defenses or patches available to mitigate the threat.

Understanding zero-day vulnerabilities is crucial in cybersecurity because they can lead to serious breaches and allow unauthorized access to sensitive information. Recognizing that a vulnerability needs to be addressed before it can be actively exploited is an essential component of security management.