Researchers at cyber security company SOCRadar have reported finding sensitive data belonging to thousands of Microsoft customers on a on a misconfigured public server.

The researchers have reported that the data includes over 335,000 emails, 133,000 projects, and that 548,000 exposed users and could be the most significant B2B data leak in the recent history of cyber security. Microsoft, however, has commented that “SOCRadar has greatly exaggerated the scope of this issue” and that its own investigation “found no indication customer accounts or systems were compromised.”

That said, Microsoft has commented that it is “directly notifying impacted customers,” and that if other Microsoft customers have not yet received a Message Centre communication, they should assume that the investigation has not identified an impact to their organisation.