What Is a Zero-Day Exploit and Why Is It So Dangerous?

This article explains what zero-day exploits are, why they are dangerous, and how they are used by actors such as the ransomware group C10p, which in 2024 exploited two zero-day vulnerabilities in Cleo file transfer software (CVE-2024-55956 and CVE-2024-50623) to breach dozens of supply-chain vendors; it outlines common targets, delivery methods, detection and mitigation strategies, and the need for supply-chain visibility and real-time threat detection.