** Windows Update -- important security risk, read and patch ASAP. **
The NSA has notified Microsoft of a serious vulnerabilty in Windows 10, and some of the Server versions, which is related to the authentication of secure web connections.
Ars Technica has an article, it's also all over the Tech press probably.
For the NSA to come out and give away this (an exploitable error) is an indication of how serious it is.
@mandlebro I heard a comment that someone bought an exploit and NSA decided to burn it to deny them using it.
@design_RG It means that enough people are using it that it is not valuable for them to hold on to it.