A new release of the Ubuntu Cloud Images for stable Ubuntu release 16.04 LTS (Xenial Xerus) is available at [1]. These new images superseded the existing images [2]. Images are available for download or immediate use on EC2 via publish AMI ids. Users who wish to update their existing installations can do so with:
   'sudo apt-get update && sudo apt-get dist-upgrade && sudo reboot'.

The following packages have been updated. Please see the full changelogs
for a complete listing of changes:
 * linux-meta: 4.4.0.204.210 => 4.4.0.206.212 
 * linux-signed: 4.4.0-204.236 => 4.4.0-206.238 
 * unattended-upgrades: 1.1ubuntu1.18.04.7~16.04.6 => 1.1ubuntu1.18.04.7~16.04.7 


The following is a complete changelog for this image.
new: {'linux-headers-4.4.0-206-generic': '4.4.0-206.238', 'linux-headers-4.4.0-206': '4.4.0-206.238', 'linux-modules-4.4.0-206-generic': '4.4.0-206.238'}
removed: {'linux-modules-4.4.0-204-generic': '4.4.0-204.236', 'linux-headers-4.4.0-204-generic': '4.4.0-204.236', 'linux-headers-4.4.0-204': '4.4.0-204.236'}
changed: ['linux-headers-generic', 'linux-headers-virtual', 'linux-image-4.4.0-206-generic', 'linux-image-virtual', 'linux-virtual', 'unattended-upgrades']
new snaps: {}
removed snaps: {}
changed snaps: []
==== linux-meta: 4.4.0.204.210 => 4.4.0.206.212 ====
====     linux-headers-generic linux-headers-virtual linux-image-virtual linux-virtual
  * Bump ABI 4.4.0-206
  * Bump ABI 4.4.0-205
==== linux-signed: 4.4.0-204.236 => 4.4.0-206.238 ====
====     linux-image-4.4.0-206-generic
  * Master version: 4.4.0-206.238
  * Master version: 4.4.0-205.237
==== unattended-upgrades: 1.1ubuntu1.18.04.7~16.04.6 => 1.1ubuntu1.18.04.7~16.04.7 ====
====     unattended-upgrades
  * data: add md5sum history file on the data folder (LP: #1915547)
    - This file contains the md5sum of the current xenial and trusty
      version of 50unattended-upgrades. This file will be used to avoid
      prompting users about unattended-upgrade changes when upgrading
      from trusty to xenial.
  * debian/postint: make ucf command reference the md5sum history file

--
[1] http://cloud-images.ubuntu.com/releases/xenial/release-20210329.1/
[2] http://cloud-images.ubuntu.com/releases/xenial/release-20210316/