Opera pushed out an update to its popular web browser on Tuesday that fixes vulnerabilities it described as "extremely severe".
Opera has released version 9.63 of its browser as a “recommended security upgrade” that fixes at least seven security vulnerabilities, some with serious risk implications.http://blogs.zdnet.com/security/?p=2315
So 3 of the major browser vendors all release major security patches at the same time! …this is a bit confusing…just when we decided which browser is best…so the winner is? 
I think the ‘extremely severe’ description comes only from The Register. There is nothing in the change details to back this up other than it cures several vulnerabilities, one or two known about before.
We really need to put things into perspective. The current problem in IE seems to have been blown up out of all proportion (mainly by MS), after all vulnerabilities in that browser are hardly unknown and they still have a lot they have never patched. This update to Opera brings it back to the ‘no known vulnerabilities’ state and all of the cured ones are VERY recent. Opera certainly does a good job of patching these things efficiently and speedily.
Opera have called 2 of the vulnerabilities as extremely critical, but my guess is that they don’t want
to go into details by now by obvious reasons. 
HL