CVE-2015-1631
Microsoft Exchange Server 2013 SP1 and Cumulative Update 7 allows remote attackers to spoof meeting organizers via unspecified vectors, aka "Exchange Forged Meeting Request Spoofing Vulnerability."
Date published : 2015-03-11
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2015/ms15-026