german Umlaute in attachments broken

if you attach a pdf (probably all other attachement types are affected as well) to a page where the filename contains a umlaut like "äüö.pdf" you cant:

• link to that attachment (link is greyed out and does not work)
• view it (returns a "Page Not Found" error)
• remove it (returns a "Not Permitted: You are not permitted to perform this operation." error)
• view/edit properties (returns a

  java.lang.NullPointerException
      at com.atlassian.confluence.pages.actions.MoveAttachmentAction.bootstrap(MoveAttachmentAction.java:112)

  should i include the full stack trace?

**Workaround**
Cloud users will need to create a support ticket for us to apply the workaround. Please provide a suitable downtime for a maintenance update when creating the support ticket.