https://wccftech.com/more-cumulative-updates-out-for-olders-versions-of-windows-10/

Microsoft is apparently releasing more Windows 10 cumulative updates following the scheduled release on Patch Tuesday last week. The updates are out for Windows 10 versions 1803, 1709, 1703, and 1607.

The latest update brings the build number up to 17134.915 for Windows 10 April 2018 Update. Here’s the changelog of this release (KB4507466):