The Register is reporting on a security flaw in mobile Java that could allow hackers to gain control of users' mobile phones. This is one of the first major security problems for a large number of mobile phones.
Exploits include: the ability to access and steal data from the phone (phonebook information, SMS messages, information about dialled numbers, etc.), sending arbitrary SMS messages to arbitrary phone numbers and transferring data to and form the net without a user's knowledge.
There is no word on when or how a fix will be sent to mobiles. We'll keep you posted.