Apollo Router is a configurable, graph router written in Rust to run a federated supergraph that uses Apollo Federation 2. The affected versions of Apollo Router contain a bug that in limited circumstances, could lead to unexpected operations being executed which can result in unintended data or effects. This only affects Router instances configured to use distributed query plan caching. The root cause of this defect is a bug in Apollo Router’s cache retrieval logic: When this defect is present and distributed query planning caching is enabled, asking the Router to execute an operation (whether it is a query, a mutation, or a subscription) may result in an unexpected variation of that operation being executed or the generation of unexpected errors. The issue stems from inadvertently…