https://transfer.sh/ is another neat service which allows you to upload a file easily using a tool such as curl and get a shareable link. There was one time when I only had Chrome Remote Desktop access to a machine without root, where this was a convenient way to share some files.
additionally, the file is automatically cleared when it goes unused for a while. There is also FEX[2], which is geared more towards power-users and includes bi-directional transfers. Both are fully self-hosted and trivial to set-up.