If a knowledge base has no access details specified, what users are able to read articles in that knowledge base?

While itil users often interact with knowledge, this is not the default access for *all* active users when no specific criteria are set.

The kb_user role provides specific knowledge management capabilities, but it's not a prerequisite for simply reading articles when no other access is defined.

When no specific user criteria are defined for a knowledge base, the system defaults to allowing access to any active user within the instance, ensuring content is broadly available unless explicitly restricted.

This is incorrect; the default behavior is to allow broad access, not to restrict all access.

A permalink provides a direct link, but access is still governed by underlying access control; a permalink alone does not grant access.