View update status for all sites in a multi-site setup:
drush @sites ups
View update status for one site of a multi-site setup:
drush -l example.com ups
Reference: Use Drush to update multi-site setup
View update status for all sites in a multi-site setup:
drush @sites ups
View update status for one site of a multi-site setup:
drush -l example.com ups
Reference: Use Drush to update multi-site setup
Other pages possibly of interest:
This website is a personal resource. Nothing here is guaranteed correct or complete, so use at your own risk and try not to delete the Internet. -Stephan