Parse Server before 8.6.109 and 9.0.0 before 9.10.6-alpha.1 returns stored field values in object update responses without checking read access, so clients whose class-level permissions or object ACLs allow update but not read can see object data. Attackers can update such objects to read atomic operation results (Increment, Add, AddUnique, Remove), Cloud Code trigger-set values, and, for dot notation keys under certain conditions, the whole stored parent field.