Most likely...
To reproduce this bug, Create an Upload Folder. Upload a blank text file to it and the content will have.
Content-Disposition: form-data; name="fileupload2"; filename=""
Content-Type: application/octet-stream
appended to the end of the text (if there is some text in the file), i think this happens with all text files but i am too tired to continue testing.
Here are some screenshots, and a screenshot from my end.