A zero-day attack is a cyberattack that takes advantage of a previously unknown vulnerability in a computer system. This vulnerability is called a zero-day vulnerability, and the attack is carried out using a zero-day exploit. The term "zero-day" refers to the fact that the vendor or developer has zero days to fix the flaw because malicious actors can already use it to gain access to vulnerable systems
. Zero-day attacks are especially dangerous because the only people who know about them are the attackers, and they can cause significant damage to affected systems
