django CMS: Broken access control in page *Duplicate* allows reading the content of any page (cross-site / restriction bypass)

ImpactThe only authorization gate on the duplicate flow is PageAdmin.hasaddpermission,which checks usercanaddpageuser, site / usercanaddsubpage... — i.e. “maythis user create a page at all”. Nothing checks the user’s relationship to the page beingcopied:- cms/admin/forms.py —...