Adobe and Sun have released patches for several critical
vulnerabilities that affect their respective Flash Player and Java
Runtime Environment. Many of these vulnerabilities can be exploited to
execute arbitrary code on victims' computers just by making them access
a malicious URL using any application that invokes Flash Player or JRE.

Many
of the vulnerabilities are cross-platform, and between them, they have
most OS-browser combinations covered. You are vulnerable until you
install the patches. Read the advisories from the vendors and grab the
patches here and here.

There
are no reported in-the-wild exploits yet, but we might see some soon as
enough technical information required to build an exploit has been
released publicly for at least a few of these vulnerabilities.