Tonight is Patch Tuesday October 11, 2011. Microsoft will ship 8 security bulletins to address at least 23 documented vulnerabilities affecting the Internet Explorer browser, the Microsoft Windows operating system, .NET Framework and Silverlight, Microsoft Forefront UAG, and Microsoft Host Integration Server.

Two patches affecting IE, Windows and .Net Framework and Silverlight are rated “critical”, usually meaning that vulnerabilities can be exploited remotely to launch code execution attacks without user knowledge.
Six bulletins will are rated “important”.
Some of these patches will require a restart after the affected machine is updated.

So leave your computer on tonight and be sure to restart it in the morning.