Microsoft has re-released one of the August security patches for Windows Server 2008 in order to fix a regression issue that would cause some servers to stop working. The MS13-066 patch was released again Monday after Microsoft discovered the problem last week. The patch fixes a vulnerability in Active Directory Federation Services that could enable an attacker to cause a denial-of-service condition on a vulnerable server under the right circumstances. Customers who already installed the original updates will be reoffered the 2843638 update.
Source: https://threatpost.com/microsoft-reissues-ms13-066-windows-server-patch/102029/