A new version of Pidgin came out last week. It fixes a potential issue where a remote MSN user could send a message that could execute arbitrary code on a victim's computer. This could be mitigated by only allowing people on your contacts list to contact you. This is wise behavior regardless of such flaws as this. If you allow any random person to contact you, it can be quite annoying.
The world of security has been somewhat unexciting as of late. That's probably a good thing.
Linux Kernel privilege escalation
The most interesting security story last week was probably a new kernel privilege escalation flaw. If you simply run something like a single user desktop machine, flaws such as this aren't all that serious, as it's unlikely there are any untrusted users on your system.
Things like servers pose a much greater risk where it's likely you have untrusted users able to execute arbitrary code on the machine in question. A flaw such as this would allow such a user to run commands as root. If this is your setup, there is a possible mitigation.