Severity Rating: Important
Revision Note: V1.2 (September 25, 2015): Added a footnote to the Affected Software table to inform customers that Windows Server Technical Preview 2 is affected. Customers running this operating system are encouraged to apply the update, which is available via Windows Update.
Summary: This security update resolves vulnerabilities in Microsoft .NET Framework. The vulnerabilities could allow elevation of privilege if a user runs a specially crafted .NET application. However, in all cases, an attacker would have no way to force users to run the application; an attacker would have to convince users to do so.
Source: ms-security