Again, sorry for posting this as it's been publicized for a few days
now. I wouldn't consider this a "critical" vulnerability, but it can,
say, allow one site to read another's cookies. Setting your cookies to
session-only in Mozilla or Opera, and then closing out your browser
and restarting frequently can take care of this problem while still
allowing the use of JavaScript.

http://www.secunia.com/advisories/9017/

Sponge
Sponge's Anti-Spyware Source
www.geocities.com/yosponge