XSS in poll title and poll answers when watching preview

Steps to reproduce
1. User creates new topic, fills title and message content fields with correct text
2. User creates poll with title

<script>alert("Hacked poll title")</script>

and one of poll answer is

<script>alert("Hacked poll answer")</script>

3. Press "Preview" button

Actual result
User receives two pop up windows with text

Hacked poll title

and

Hacked poll answer

Poll title and answer are empty

Expected result
There is no any additional windows