A security researcher publically disclosed a zero-day vulnerability in Windows 10, Windows 8.1 and Server editions. The flaw resides in the implementation of the SMB (server message block) network file sharing protocol. The vulnerability has been given Common Vulnerability Scoring System (CVSS) score of 7.8. Microsoft has downplayed the severity of the issue, saying: “Windows is the only platform with a customer commitment to investigate reported security issues, and proactively update impacted devices as soon as possible”
Source: https://thehackernews.com/2017/02/windows-smb-0day.html