Yes, the NSA discovered a major security threat in the Windows 10 operating system. No, the Russians are not suddenly hacking you.

The IT world was waiting on pins and needles yesterday for a high profile Microsoft Windows 10 security patch, and the US National Security Agency (NSA) has enlightened us as to why. Apparently the government agency has discovered a serious flaw in Windows 10 that could expose users to surveillance or serious data breaches.

The NSA confirmed (link) that the vulnerability affects Windows 10 and Windows Server 2016. It said that it flagged the dangerous bug because it "makes trust vulnerable." However, it wouldn't say when it found the flaw and declined to discuss it further until Microsoft released a patch.

The vulnerability was found in a Windows component called crypt32.dll, which handles "certificate and cryptographic messaging functions," according to Microsoft. An exploit in that area could affect authentication on Windows desktops and servers, sensitive data on Microsoft's Internet Explorer and Edge browsers and many third-party applications. Hackers could also use it to spoof digital signatures, making malware look like a legitimate app.

A software patch was released yesterday to critical Windows 10 clients including the US military and managers of key internet infrastructure. Microsoft has since released updates for all customers, urging them to install them "as quickly as practical." as this flaw is being noted the second most severe in Microsoft's rating system. Microsoft has confirmed it has not yet been exploited, but is still a major security issue.