Not just security, archive.ubuntu and releases.ubuntu as well. Same thing happened Jan 13th. Quick fix is to switch to a mirror: https://launchpad.net/ubuntu/+a

Not just security, archive.ubuntu and releases.ubuntu as well. Same thing happened Jan 13th. Quick fix is to switch to a mirror: https://launchpad.net/ubuntu/+archivemirrors https://launchpad.net/ubuntu/+archivemirrors EDIT: I'm in Germany.