Can't navigate to subsite without logging in again.

[davidmlentz]

In a multi-site configuration, as a Super Admin user, log in to the root site. Then navigate to the dashboard of a subsite.

Expected result: navigate to the subsite unhindered.
Actual result: prompted to log in before navigating to the subsite.

Problem occurs when we use WP Core 4.7. Problem does not occur on WP Core 4.6.

Problem occurs when all plugins are deactivated and uninstalled.

Problem occurs on more than one theme.

[kevinlangleyjr]

@davidmlentz - Is this for a subdomain or subdirectory multisite install? I've tested on both a fresh subdirectory and subdomain install and don't see any issues.

[davidmlentz]

Replying to kevinlangleyjr:

@davidmlentz - Is this for a subdomain or subdirectory multisite install? I've tested on both a fresh subdirectory and subdomain install and don't see any issues.

Subdirectories. My test case has me first log in here:
​https://dev-oit.boisestate.edu/wp-admin/

Then move to here:
​https://dev-oit.boisestate.edu/email/wp-admin/

...at which point I'm prompted to log in again.

[anonymized_14169293]

This is also happening in multisite with the "new" native domain mapping functionality. Even when you are a Super Admin, you need to logging-in in each site and subsite individually.

[realloc]

ms_cookie_constants() is effectively unchanged between 4.6 and 4.7, so for a subdirectory install, ADMIN_COOKIE_PATH and COOKIEPATH both resolve to /, and the cookies also apply to /email/wp-admin/. No re-login should be required. This matches comment:2, where the issue could not be reproduced on fresh installs.

This does not look like a core regression, but rather an environment-specific issue (HTTPS behind a reverse proxy, or manually defined cookie constants in wp-config.php).

@davidmlentz, could you confirm whether the site runs behind a proxy with SSL termination, and whether it reproduces on a clean 4.7 subdirectory install? Without a reproducible case, I suggest closing this ticket.