A new release of the Ubuntu Cloud Images for stable Ubuntu release 16.04 () 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 These new images superseded the existing images [2].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: 4.4.0-64.85 => 4.4.0-66.87 
 * linux-meta: 4.4.0.64.68 => 4.4.0.66.70 
 * mdadm: 3.3-2ubuntu7.1 => 3.3-2ubuntu7.2 


The following is a complete changelog for this image.
new: {'linux-headers-4.4.0-66-generic': '4.4.0-66.87', 'linux-headers-4.4.0-66': '4.4.0-66.87'}
removed: {'linux-headers-4.4.0-64-generic': '4.4.0-64.85', 'linux-headers-4.4.0-64': '4.4.0-64.85'}
changed: ['linux-image-virtual', 'linux-headers-virtual', 'mdadm', 'linux-virtual', 'linux-image-4.4.0-66-generic', 'linux-headers-generic']
==== mdadm: 3.3-2ubuntu7.1 => 3.3-2ubuntu7.2 ====
====     mdadm
  * Backport initramfs changes from 3.4-4, to improve reliability of
    booting with degraded arrays. LP: #1635049
  * debian/initramfs/hook:
    - Fix UUID= grep for configured RAIDs to be case insensitive.
    - Drop CREATE stanzas from mkconf and don't include them in the
    initramfs. The generated defaults, are the compiled-in defaults. And
    the current one generates warnings when running mdadm in the
    initramfs, as there is no passwd|group files to resolve root/disk
    uid/gid.
  * debian/initrmafs/script.local-block|script.local-bottom:
    - Use local-block integration scrips, in favor of root-fail hooks to
    activate incomplete arrays.
  * debian/initramfs/init-premount|mdadm-functions:
    - Drop, no longer in use.
==== linux-meta: 4.4.0.64.68 => 4.4.0.66.70 ====
====     linux-headers-generic linux-image-virtual linux-headers-virtual linux-virtual
  * Bump ABI 4.4.0-66
  * Bump ABI 4.4.0-65
==== linux: 4.4.0-64.85 => 4.4.0-66.87 ====
====     linux-image-4.4.0-66-generic
  * CVE-2017-2636
    - TTY: n_hdlc, fix lockdep false positive
    - tty: n_hdlc: get rid of racy n_hdlc.tbuf

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[1] http://cloud-images.ubuntu.com/releases/xenial/release-20170307/
[2] http://cloud-images.ubuntu.com/releases/xenial/release-20170303/