FreeScout IDOR Vulnerability: PERM_EDIT_USERS allows modifying any user's notification subscriptions (incomplete fix of CVE-2025-48472)

FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.217, a user holding the PERM_EDIT_USERS permission (intended for general user-profile editing) can read and modify the notification subscriptions of any other user, including admins, by sending a single POST request. This is a sibling of CVE-2025-48472's notification authorization bypass — the prior fix did not cover this code path. A non-admin attacker can silently disable an admin's email/browser/mobile notifications, suppressing security alerts and conversation-assignment notices. This issue has been patched in version 1.8.217.