Affected updates are Java v1.6 Update 41 and Java v1.7 Update 15 (released on February 19), and the vulnerability leads to arbitrary memory read and write in the Java Virtual Machine (JVM) process.
The silver lining in all of this is that the exploit is not very reliable as it tries to overwrite a big chunk of memory. But, if it succeeds, the McRAT dropper and information stealer Trojan is downloaded onto the victim's computer.
FireEye has notified Oracle about the flaw, so you can look forward to a new update - hopefully very soon! In the meantime, the researchers are advising users to disable Java.
Still - aren't you tired of this never-ending back and forth? If you are, consider permanently disabling Java in the browser you use, then see if you miss it.
If you really need it for viewing specific websites you visit daily, use an alternative browser with enabled Java just to visit those few sites, and keep the primary one for burrowing the depths of the Internet.