This question was asked in 2013, but the answer is out of date (plugin retired).
My question is:
We want to install WordPress multisite with blog1.site.com, blog2.site.com, etc., all having single sign on.
We need to make the transition between the sites seamless so they appear well-integrated as part of one domain.
How can I make the same user logged in one of my sites automatically logged in when visit any other site from network?
I am also searching for a solution to this problem. I also found many SSO outdated/unsupported plugins and do not want to install them for security reasons.
The closest solution I could find is from here
How do I share user logins and roles across the multisite network?
By default, a user who is registered on one site cannot register or be added to another site on the same network. That’s because they are already registered in the shared WordPress database. However, they don’t have any user role privileges on other sites.
You can use third-party plugins like WP Multisite User Sync to sync users across the network. However, you need to be careful as you may end up giving someone admin privileges to a site.
But I haven't tested it thoroughly enough yet to see if it satisfies everything I need and I'm not sure where to deal with the problem mentioned in the article of "you may end up giving someone admin privileges".
If anyone else has a solution closer to the WPMUDEV SSO plugin that would be very helpful. Thanks
