By the Associated Press:

The National Security Agency has discovered a major security flaw in Microsoft’s Windows 10 operating system that could allow hackers to intercept seemingly secure communications. But rather than exploit the flaw for its own intelligence needs, the NSA tipped off Microsoft so that it can fix the system for everyone.

Microsoft released a free software patch to fix it Tuesday and credited the agency for discovering the flaw. The company says it hasn’t seen any evidence that hackers have used the technique.

One expert says this is a good example of the “constructive role” that the NSA can play in improving global information security.