The most serious flaw (MS16-001) affecting Internet Explorer could allow an attacker to remotely execute code by tricking a user into visiting a specially-crafted webpage. The attacker would gain the same user rights as the current user, which puts administrators at a greater risk.
Though one of the vulnerabilities was publicly disclosed, Microsoft said it wasn't aware of any attacker exploiting the flaw.
Microsoft Edge, the new browser exclusive to Windows 10, also gets updated with a cumulative update. The most serious flaw (MS16-002) also allows an attacker to remotely execute code from a specially-crafted webpage.
Windows Server 2016 Tech Previews 3 and 4 are affected by both bulletins, and require patching.