Mautic: SQL Injection via field Parameter in Lead-by-Field-Value AJAX Endpoint

Mautic's getLeadIdsByFieldValueAction (LeadBundle/Controller/AjaxController.php) reads a field parameter from the request, sanitizes it only with InputHelper::clean() (which HTML-entity-encodes quotes and angle brackets but does not restrict other characters), and passes it into LeadRepository::buildQueryForGetLeadsByFieldValue() where it is concatenated directly as a raw SQL column identifier ($col = 'l.'.$field) rather than being validated against a whitelist of real column names or passed as a bound parameter. Since Doctrine cannot parameterize identifiers, and the sanitizer does not block spaces, parentheses, or other SQL-relevant characters, an attacker can inject SQL via the field name itself. The action requires only a valid session (any authenticated user), unlike sibling actions in the same controller that carry additional permission checks.