Django-Select2 is a Django integration for Select2. Prior to version 8.4.1, instances of HeavySelect2Mixin subclasses like the ModelSelect2MultipleWidget and ModelSelect2Widget can leak secret access tokens across requests. This can allow users to access restricted query sets and restricted data. This issue has been patched in version 8.4.1.
https://github.com/codingjoe/django-select2/security/advisories/GHSA-wjrh-hj83-3wh7
https://github.com/codingjoe/django-select2/commit/e5f41e6edba004d35f94915ff5e2559f44853412