As you may know (or not) there is a vulnerability found in OpenSSL. This Open Source library is used all over the place like Apache web servers, SSH, VPN, etc. so this is a big one.
You can read more about it at http://heartbleed.com .
Also PostgreSQL uses OpenSSL for it's SSL connections.
PostgreSQL core member Magnus Hagander did a brief writeup about this vulnerability and how it affects PostgreSQL.
http://blog.hagander.net/archives/219-P ... ility.html
And as Magnus already mentioned in his blog, don't forget to restart your services after updating as the OpenSSL update doesn't do that for you.