MuscleNerd announced a few minutes ago on Twitter that the Dev Team is releasing the first public jailbreak for iPhone OS 4.0 beta 1. This beta release comes roughly a week after the Dev Team jailbroke iPhone OS 4.
Although new, this jailbreak uses same pwnage2 DFU exploit that’s been out for a few years so nothing major has been revealed to Apple.
In short, if you’re an average iPhone user, you should stay clear from this jailbreak.
RedSn0w 0.9.5 beta currently supports the iPhone 3G only and only works on Mac OSX, since jailbreak apps are developed on this platform.
For more information as well as directions on how to use the beta RedSn0w 0.9.5 to jailbreak the iPhone 4.0 beta 1, check out the Dev Team wiki.
Note that this jailbreak is for iPhone OS 4 beta 1 only. It will not jailbreak or unlock any other firmware.