API Platform Core is a system to create hypermedia-driven REST and GraphQL APIs. Prior to 4.0.22, a GraphQL grant on a property might be cached with different objects. The ApiPlatformGraphQlSerializerItemNormalizer::isCacheKeySafe() method is meant to prevent the caching but the parent::normalize method that is called afterwards still creates the cache key and causes the issue. This vulnerability is fixed in 4.0.22.
The product performs multiple related behaviors, but the behaviors are performed in the wrong order in ways which may produce resultant weaknesses.