From pandasecurity.com
Cyber-incidents that stem from security vulnerabilities have always been, and still are, a major cyber-security issue. Notable cyber-attacks that have exploited vulnerabilities include WannaCry, the Equifax data breach, and Stuxnet, among many others.
There is a tendency to believe that zero-day vulnerabilities represent the greatest threat, as victims are unaware of the danger, yet this is far from true. More than 90 percent of successful attacks could have been avoided simply by patching software.