A new release of the Ubuntu Cloud Images for stable Ubuntu release 21.04 (Hirsute Hippo) 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 These new images superseded the existing images [2].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:
 * cloud-init: 21.1-19-gbad84ad4-0ubuntu3 => 21.2-3-g899bfaa9-0ubuntu2~21.04.1 
 * isc-dhcp: 4.4.1-2.2ubuntu6.1 => 4.4.1-2.2ubuntu6.2 
 * policykit-1: 0.105-30 => 0.105-30ubuntu0.1 
 * procps: 2:3.3.16-5ubuntu3 => 2:3.3.16-5ubuntu3.1 
 * ubuntu-release-upgrader: 1:21.04.12 => 1:21.04.13 
 * update-notifier: 3.192.40.2 => 3.192.40.3 


The following is a complete changelog for this image.
new: {}
removed: {}
changed: ['cloud-init', 'isc-dhcp-client', 'isc-dhcp-common', 'libpolkit-agent-1-0:amd64', 'libpolkit-gobject-1-0:amd64', 'libprocps8:amd64', 'policykit-1', 'procps', 'python3-distupgrade', 'ubuntu-release-upgrader-core', 'update-notifier-common']
new snaps: {}
removed snaps: {}
changed snaps: ['lxd']
==== cloud-init: 21.1-19-gbad84ad4-0ubuntu3 => 21.2-3-g899bfaa9-0ubuntu2~21.04.1 ====
====     cloud-init
  * d/cloud-init.templates: Add Vultr datasource support
  * drop the following cherry-picks now included:
    + cpick-83f6bbfb-Fix-unpickle-for-source-paths-missing-run_dir-863
    + cpick-d132356c-fix-error-on-upgrade-caused-by-new-vendordata2
  * New upstream snapshot. (LP: #1927491)
    - Update test characters in substitution unit test (#893)
    - cc_disk_setup.py: remove UDEVADM_CMD definition as not used (#886)
      [dermotbradley]
    - Add AlmaLinux OS support (#872) [Andrew Lukoshko]
    - Release 21.2 (#890)
    - Add \r\n check for SSH keys in Azure (#889)
    - Revert "Add support to resize rootfs if using LVM (#721)" (#887)
    - Add Vultaire as contributor (#881) [Paul Goins]
    - Azure: adding support for consuming userdata from IMDS (#884) [Anh Vo]
    - test_upgrade: modify test_upgrade_package to run for more sources (#883)
    - Fix chef module run failure when chef_license is set (#868) [Ben Hughes]
    - Azure: Retry net metadata during nic attach for non-timeout errs (#878)
      [aswinrajamannar]
    - Azure: Retrieve username and hostname from IMDS (#865) [Thomas Stringer]
    - Azure: eject the provisioning iso before reporting ready (#861) [Anh Vo]
    - Use `partprobe` to re-read partition table if available (#856)
      [Nicolas Bock]
    - fix error on upgrade caused by new vendordata2 attributes (#869)
    - add prefer_fqdn_over_hostname config option (#859) [hamalq]
    - Emit dots on travis to avoid timeout (#867)
    - doc: Replace remaining references to user-scripts as a config module
      (#866) [Ryan Harper]
    - azure: Removing ability to invoke walinuxagent (#799) [Anh Vo]
    - Add Vultr support (#827) [David Dymko]
    - Fix unpickle for source paths missing run_dir (#863) [lucasmoura]
    - sysconfig: use BONDING_MODULE_OPTS on SUSE (#831) [Jens Sandmann]
    - bringup_static_routes: fix gateway check (#850) [Petr Fedchenkov]
    - add hamalq user (#860) [hamalq]
    - Add support to resize rootfs if using LVM (#721) [Eduardo Otubo]
    - Fix mis-detecting network configuration in initramfs cmdline (#844)
    - tools/write-ssh-key-fingerprints: do not display empty header/footer
      (#817) [dermotbradley]
    - Azure helper: Ensure Azure http handler sleeps between retries (#842)
      [Johnson Shi]
    - Fix chef apt source example (#826) [timothegenzmer]
==== isc-dhcp: 4.4.1-2.2ubuntu6.1 => 4.4.1-2.2ubuntu6.2 ====
====     isc-dhcp-client isc-dhcp-common
  * Fix regression caused by rebuild with newer toolchain (LP: #1930917)
    - debian/rules: build with -fno-strict-aliasing.
==== policykit-1: 0.105-30 => 0.105-30ubuntu0.1 ====
====     libpolkit-agent-1-0:amd64 libpolkit-gobject-1-0:amd64 policykit-1
  * SECURITY UPDATE: local privilege escalation using
    polkit_system_bus_name_get_creds_sync()
    - debian/patches/CVE-2021-3560.patch: use proper return code in
      src/polkit/polkitsystembusname.c.
    - CVE-2021-3560
==== procps: 2:3.3.16-5ubuntu3 => 2:3.3.16-5ubuntu3.1 ====
====     libprocps8:amd64 procps
  * d/p/ignore_eaccess.patch
    - Fix conflict with 7af88da3 and adjust logic (LP: #1903351)
  * d/p/ignore_erofs.patch
    - Fix conflict with 7af88da3 and adjust logic (LP: #1903351)
==== ubuntu-release-upgrader: 1:21.04.12 => 1:21.04.13 ====
====     python3-distupgrade ubuntu-release-upgrader-core
  * tests/test_sources_list.py: switch from precise to focal (for ports too!)
    as precise was removed from the archive.
  * DistUpgradeQuirks.py: only block upgrades for Apple hardware not all
    hardware that doesn't have DMI information. Thanks to Alyssa Rowan for the
    patch. (LP: #1931112)
  * Run pre-build.sh: updating mirrors, demotions, and translations.
==== update-notifier: 3.192.40.2 => 3.192.40.3 ====
====     update-notifier-common
  * debian/control: add lsb-release to the update-notifier-common depends as
    it is used by apt-cdrom-check. (LP: #1927996)
  * data/apt_check.py
    - Only show esm-apps alerts on lts and non-esm distros (LP: #1926990)
    - Update esm-infra alert for distros on ESM mode
    - Show message with number of upgradable packages even if that
      number is zero (LP: #1926819)
    - Get distro name and version directly from /etc/os-release
    - Fallback to lsb_release command if there are any problems using
      /etc/os-release as source of information
    - Show esm-apps status header when running on LTS distro that
      has not yet entered Extended Security Maintenance

--
[1] http://cloud-images.ubuntu.com/releases/hirsute/release-20210615/
[2] http://cloud-images.ubuntu.com/releases/hirsute/release-20210603/