Safari provides users with the option for reporting browser bugs to Apple. Click the Safari menu and select Report Bugs to Apple from the menu list.
This would display the following window where you can enter the web page address and the description of the error occurred.
Using the Problem type drop down, you can specify the exact problem whether it was a Crash or Can’t log in etc..
You can also attach the Screenshot and source of the error page while reporting by marking the required check boxes.
After entering the required details, click on the Submit button to report the issues faced in Safari to Apple.