This is one that people have been getting wrong for decades.
"A zero-day (also known as 0-day) vulnerability is a computer-software vulnerability that is unknown to those who would be interested in mitigating the vulnerability (including the vendor of the target software)" Patching and knowing about the vulnerability are different things.
"A zero-day (also known as 0-day) vulnerability is a computer-software vulnerability that is unknown to those who would be interested in mitigating the vulnerability (including the vendor of the target software)" Patching and knowing about the vulnerability are different things.
And so, this is not 0day.