Apple has a serious problem on its hands. It's not the kind of problem that crashes a Messaging app, something that you can move on from and come back to later. It's the kind of problem that leaves Macs at-risk to hackers gaining access to some of the most important parts of the computer, without detection.
First discovered by Portugese computer security researched Pedro Vilaça, the security flaw known as "Apple Mac OS X EFI Firmware Security Vulnerability" is likely present in Macs older than one year that enter a hibernation state. Upon waking up, the EFI of the Mac is unlocked and can be toyed with at-will by a hacker who has gained access. This gives way to the potential of big hacks like "Dark Jedi" to occur and create a bad day for the Mac owner.
Everyday users shouldn't worry too much about this specific hack since it's a complicated process that would probably be more suitable for a high-risk/high-reward hack. However, computer security workers within companies that have valuable data that could cripple the company if manipulated or removed should be aware of the vulnerability.
Apple has been alerted to the Dark Jedi security flaw but have not yet issued any statements.
[UPDATE] - Corrected the use of BIOS within Macs to the proper EFI designation. Dark Jedi also isn't the name of the vulnerability but has been associated with the vulnerability.