https://www.techradar.com/news/apple-releases-yet-another-high-sierra-beta-while-we-still-wait-for-macos-10135

Apple has released yet another beta update for macOS High Sierra, which will have the version number 10.13.6.

This is the fourth beta that Apple has released for High Sierra in May alone, which shows that the company is working hard on getting the new version of the operating system out to developers who have signed up for early builds.