Symfony UX is a JavaScript ecosystem for Symfony. From 2.2.0 until 2.36.0 and 3.1.0, Symfony\UX\Autocomplete\Doctrine\EntitySearchUtil::addSearchClause() builds the LIKE expression used by the autocomplete endpoint by wrapping the client-supplied query in %...% without escaping SQL LIKE wildcards (%, _, \), allowing unauthenticated users to turn the public BaseEntityAutocompleteType endpoint into a broad matcher or blind boolean oracle against every column in default searchable_fields. This issue is fixed in versions 2.36.0 and 3.1.0.