There is a fresh bug in WordPress 4.3, it will cause a race condition in the wordpress cron, and the contents option_value of the option_name cron in wp_options will continue growing.
It will continue growing unchecked, this caused our binary log to fill up the disk.
You can check the size of the cron with:
mysql> select option_name,length(option_value) from wp_options where option_name ='cron';
If it continues growing unchecked you have hit the bug.
Here is the mailing list discussion of the bug:
Here is the changelist with the fixes for this bug
If after applying the patch the old crontasks don’t get executed you may need to clear the cron:
mysql> UPDATE wp_options SET option_value = '' WHERE option_name = 'cron';