XML External Entity (XXE) Vulnerability in Latest Release

[HatBoy]

Hi, I would like to report XML External Entity (XXE) vulnerability in latest release.
Description:
XML External Entity (XXE) vulnerability in quokka/utils/atom.py 157 line and auokka/core/content/views.py 94 line, Because there is no filter authors, title.
Steps To Reproduce:
1.Create a article, title and authors can insert XML payload.
2.Open the url:
http://192.168.100.8:8000/author/{author}/index.rss
http://192.168.100.8:8000/author/{author}/index.atom
can see the title and authors has inserted into the XML.

author by jin.dong@dbappsecurity.com.cn

[marcosptf]

was removed WIP from pr and fixed this issue:
hotfix ready to merge: please make your comments and reviews:
#679