Google Mandiant security analysts warn of a worrying new trend of threat actors demonstrating a better capability to discover and exploit zero-day vulnerabilities in software.
Specifically, of the 138 vulnerabilities disclosed as actively exploited in 2023, Mandiant says 97 (70.3%) were leveraged as zero-days.
This means that threat actors exploited the flaws in attacks before the impacted vendors knew of the bugs existence or had been able to patch them.
That would assume that security was a priority beforehand.
Google has been known to prioritize new projects over maintaining existing ones. That would generally lead to less defined security architecture as the system is less tested.