SA-CONTRIB-2026-249: Critical severity drupal/domain_login_restrict vulnerability

This module enables you to restrict user logins on a multi-domain site built with the Domain module, so that users can only log in on the domains assigned to them. The module doesn't sufficiently enforce these restrictions when a user logs in by a method other than the standard login form. This vulnerability is mitigated by the fact that an attacker must have a valid user account on the site, and the "Enable restriction" setting must be enabled on the Domain settings page. Users with the "Login to any domain" permission are not affected by the restriction.