Read about it here.
I think v. 7 is only available for Windows...but it's worth noting.
OPERA 7 HAS GAPING HOLES that can allow an attacker to read any of your files. The Israeli company GreyMagic Software, better known for its tireless reporting of flaws in Microsoft's Internet Explorer, has found five gaps in security in the recently launched Opera 7.
I think v. 7 is only available for Windows...but it's worth noting.