Not really, any big project has people going over every commit to see what changed. Any commits that are associated with a security release are particularly scrutinized. Within an hour of release there would already be people talking about the vulnerability, as well as example code for triggering it. Full disclosure is better, because even if people can't do an upgrade, they can choose to block ports at firewalls, turn off databases, and other mitigation methods immediately, as they are allowed to.

Hiding the information just weakens the defender position, not the attacker position. Secrecy in implementation is not security, it is just stupidity.