Nilay Patel for the Verge:

Apple just released OS X Lion 10.7.4, which fixes a nasty bug that exposed FileVault passwords in plain text if Snow Leopard users upgraded to Lion but kept using their legacy FileVault settings. (FileVault 2 in Lion never had a problem, so if you bought a new Lion machine you’re in the clear.)

Fire up Software Update and grab it, folks. Other changes afoot too, including improved SMB server compatibility, a fix to the “Reopen windows when logging back in” setting and more.