KLA10752
Denial of service vulnerability in Microsoft Acrtive Directory Federation Services

Lack of input data checks was found in Microsoft Active Directory Federation Services. By exploiting this vulnerability malicious users can cause denial of service. This vulnerability can be exploited remotely via a specially designed input to form-based authentication.

Microsoft Active Directory Federation Services 3.0

Install necessary updates from the KB section, that are listed in your Windows Update (Windows Update usually can be accessed from the Control Panel)