Apple released Thursday Java for Mac OS X 10.5 Update 5 -- a Java update for Leopard -- that includes a variety of security fixes.
Apple's patch notes said, "Java for Mac OS X 10.5 Update 5 delivers improved reliability, security, and compatibility for Java SE 6, J2SE 5.0 and J2SE 1.4.2 on Mac OS X 10.5.8 and later. This release updates Java SE 6 to version 1.6.0_15, J2SE 5.0 to version 1.5.0_20, and J2SE 1.4.2 to 1.4.2_22."
More specifically, it fixes four issues that could allow the bad guys to take over your Mac through maliciously crafted Java applets.
The update is a 161.35MB download, and you can find it at Apple's Support site, or through Software Update if you're running Mac OS X 10.5 "Leopard."