The Ubuntu team announced the release of Ubuntu 16.04.7 and 18.04.5. These versions offer up-to-date installers with package fixes rather than completely new versions of the distribution.
The new ISOs include fixes for the latest problem Boothole GRUB boot loader: 
“As with point release 16.04.6, 16.04.7 is a security release designed to provide up-to-date installations that protect new installations from 2 vulnerabilities recently discovered in GRUB 2 vulnerabilities (USN-4432-1). ”
Detailed information on USN-4432-1 can be found here find here.
"The new ISO images for information 18.04.5 are available for most community editions of Ubuntu, however only Ubuntu and Ubuntu Kylin have version 16.04.7 as this version is no longer covered by the three years of support that most community editions offer.
More information can be found in the announcements of the new releases
16.04.7 and 18.04.5.
Download
- ubuntu-16.04.7-desktop-amd64.iso (1,619MB, SHA256, signature, torrent sites),
- ubuntukylin-16.04.7-desktop-amd64.iso (1,668MB, SHA256, signature, torrent sites),
- ubuntu-18.04.5-desktop-amd64.iso (2,091MB, SHA256, signature, torrent sites),
- kubuntu-18.04.5-desktop-amd64.iso (1,908MB, SHA256, signature, torrent sites),
- lubuntu-18.04.5-desktop-amd64.iso (1,145MB, SHA256, signature, torrent sites),
- ubuntukylin-18.04.5-desktop-amd64.iso (1,788MB, SHA256, signature, torrent sites),
- ubuntu-mate-18.04.5-desktop-amd64.iso (1,964MB, SHA256, signature, torrent sites),
- ubuntu-budgie-18.04.5-desktop-amd64.iso (1,655MB, SHA256, signature, torrent sites),
- xubuntu-18.04.5-desktop-amd64.iso (1,490MB, SHA256, signature, torrent sites).
