Apple today seeded the first beta of macOS Sierra 10.12.6 to public beta testers, one day after releasing the beta to developers and two days after releasing macOS Sierra 10.12.5, a minor update with bug fixes and other improvements.
Beta testers who have signed up for the Apple beta testing program will receive the macOS Sierra 10.12.6 beta through the Software Update mechanism in the Mac App Store.

Those who want to be a part of Apple's beta testing program can sign up to participate through the beta testing website, which gives users access to both iOS and macOS Sierra betas.
No notable features were discovered in macOS Sierra 10.12.6 developer beta, suggesting this update is minor in scale and focuses on internal improvements like bug fixes and security enhancements rather than outward-facing changes.






















Top Rated Comments
They'll mail you things like (but only after final release, not on beta's)
macOS 10.12.5 is now available and addresses the following:
IOGraphics
Available for: macOS Sierra 10.12.4
Impact: An application may be able to gain kernel privileges
Description: A memory corruption issue was addressed with improved
memory handling.
CVE-2017-2545: 360 Security (@mj0011sec) working with Trend Micro's
Zero Day Initiative
This is the same case when example - Facebook does an iOS App update. It never specifies whats happened. annoying
So, no need to break the NDA. :oops: