A week Old Device which has Google launched on 24th july 2013. You can also check out our previous article What is Google Chromecast? It is a great device but their are some issues to some people while establishing connection. After seeing all these issues Google responds very quickly with an update which will fix some bugs like performance, reliability, and security.
You will start getting the update in the next few days. Current build number is 12078 with the update being 12840. There are no details as yet on exactly what is included in the software update for the Google Chromecast, you can find out more details over at Google.
Source: Google Chrome Releases