OpenFGA: Cache-key delimiter injection in openfga/openfga shared-iterator and v2 iterator caches enables intra-store authorization-decision poisoning

OpenFGA is an authorization/permission engine built for developers. Prior to version 1.16.0, when iterator caching is enabled, two distinct check requests can produce the same cache key, leading to OpenFGA reusing an earlier cached result for a subsequent request. This issue has been patched in version 1.16.0.