The Ubuntu team announced the release of Ubuntu 16.04.7 and 18.04.5. These releases offer updated media installations with package fixes and not completely new versions of the distribution.
The new ISOs include fixes for the recent Boothole GRUB boot issue loader: 
“As with point release 16.04.6, 16.04.7 is a version security measures to provide updated installation media that protect new installations from 2 vulnerabilities newly discovered in GRUB 2 vulnerabilities (USN-4432-1). ”
Detailed information for USN-4432-1 you can find here.
"The new ISO images for Update 18.04.5 is available for most community versions 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 most community versions 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).
