Shopware is an open commerce platform. The store-API works with regular entities and not expose all fields for the public API; fields need to be marked as ApiAware in the EntityDefinition. So only ApiAware fields of the EntityDefinition will be encoded to the final JSON. Prior to versions 6.6.5.1 and 6.5.8.13, the processing of the Criteria did not considered ManyToMany associations and so they were not considered properly and the protections didn't get used. This issue cannot be reproduced with the default entities by Shopware, but can be triggered with extensions. Update to Shopware 6.6.5.1 or 6.5.8.13 to receive a patch. For older versions of 6.2, 6.3, and 6.4, corresponding security measures are also available via a plugin.