Every time Apple releases a new version of iOS, there’s a good chance they have broken existing jailbreak techniques with it. If a public jailbreak has already been released, it means your jailbreak has gone away; if a public jailbreak hasn’t yet been released, an update can kill an exploit that will delay a public jailbreak by months.
Yesterday, Apple released iOS 7.0.4, but did they break the possibility of an iOS 7 jailbreak? Are you safe to update?
According to jailbreak guru MuscleNerd, iOS 7.0.4 should be a safe update:
Those at 7.x waiting for JB, maybe treat 7.0.4 as exercise in restraint. Won’t affect JB if you slip up, but test your ability to avoid it!
Even though iOS 7.0.4 is safe, what MuscleNerd is trying to warn users about is updating immediately and unthinkingly every time Apple drops a new version of iOS, without waiting to see if it’s safe. Good advice, but feel free to update to iOS 7.0.4 anyway.