Microsoft officially launched a major Windows 8 app update this week, introducing a pack of new features for all built-in Windows 8 Modern apps ahead of the public debut of Blue.
It appears that Microsoft also patched a “moderate” security vulnerability in the Mail app that could allow an attacker spoof link targets via a crafter HTML email message, as it's mentioned in an advisory.
As compared to traditional patches, fixes aimed at Modern apps aren't distributed via Windows Update, but through the integrated Windows Store.
Windows Blue, the first major refresh of Windows 8, is expected to bring several improvements for the default Modern apps, so Microsoft is trying to patch all of them before the debut of this new OS.
According to sources familiar with the matter, Blue is expected to be released sometime this summer, so don't be too surprised if other major Windows 8 app updates are launched in the coming months.