[iOS 8.3] Safari crashes (javascript) - bug report for Apple developers

Safari browser crashes while running javascript code (prompt function) after last update iOS to 8.3.

Steps to reproduce:

1) Open some Vbulletin 3 or 4 based forum, for example, hyundai-forum.com.

2) Log in (register before if not registered)

3) Open some thread in forum, for example, hyundai-forums.com/amica-atoz-forum/364929-how-tell-if-you-need-new-transmissio n-oil.html

4) Scroll down, click "+" at "Quick reply" to open quick reply area

5) Click "Insert link" (see attached screenshot)

6) Safari crashes

This appears after upgrade to iOS 8.3 (iPad and iPhone)