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 These new images superseded the existing images [2].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:
 * distro-info-data: 0.28ubuntu0.16 => 0.28ubuntu0.17 
 * dnsmasq: 2.75-1ubuntu0.16.04.8 => 2.75-1ubuntu0.16.04.10 
 * linux-meta: 4.4.0.209.215 => 4.4.0.210.216 
 * linux-signed: 4.4.0-209.241 => 4.4.0-210.242 


The following is a complete changelog for this image.
new: {'linux-modules-4.4.0-210-generic': '4.4.0-210.242', 'linux-headers-4.4.0-210': '4.4.0-210.242', 'linux-headers-4.4.0-210-generic': '4.4.0-210.242'}
removed: {'linux-headers-4.4.0-209': '4.4.0-209.241', 'linux-headers-4.4.0-209-generic': '4.4.0-209.241', 'linux-modules-4.4.0-209-generic': '4.4.0-209.241'}
changed: ['distro-info-data', 'dnsmasq-base', 'linux-headers-generic', 'linux-headers-virtual', 'linux-image-4.4.0-210-generic', 'linux-image-virtual', 'linux-virtual']
new snaps: {}
removed snaps: {}
changed snaps: []
==== distro-info-data: 0.28ubuntu0.16 => 0.28ubuntu0.17 ====
====     distro-info-data
  * Add Ubuntu 21.10, Impish Indri (LP: #1925484)
==== dnsmasq: 2.75-1ubuntu0.16.04.8 => 2.75-1ubuntu0.16.04.10 ====
====     dnsmasq-base
  * SECURITY UPDATE: Multiple security issues
    - CVE-2017-15107: wildcard NSEC records interpretation issue
      + 4fe6744a220eddd3f1749b40cac3dfc510787de6
      + cd7df612b14ec1bf831a966ccaf076be0dae7404
    - CVE-2019-14513: DoS via improper bounds checking
      + d3a8b39c7df2f0debf3b5f274a1c37a9e261f94e
==== linux-meta: 4.4.0.209.215 => 4.4.0.210.216 ====
====     linux-headers-generic linux-headers-virtual linux-image-virtual linux-virtual
  * Bump ABI 4.4.0-210
==== linux-signed: 4.4.0-209.241 => 4.4.0-210.242 ====
====     linux-image-4.4.0-210-generic
  * Master version: 4.4.0-210.242

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[1] http://cloud-images.ubuntu.com/releases/xenial/release-20210422/
[2] http://cloud-images.ubuntu.com/releases/xenial/release-20210416/