Celeb Nude Photo Leak -- Apple Says ... It Ain't Our Fault

Personal accounts of Jennifer Lawrence, Kate Upton and other celebs were all individually targeted by hackers, and Apple's iCloud security system was not to blame ... according to Apple.

Apple now says after nearly 2 days of investigating ... their research shows the hackers broke into each celeb's iCloud and/or iPhone accounts by using actual usernames, passwords and security codes.

Apple maintains it was not a breach, and says it's working with law enforcement to find the suspect or suspects involved.