diff --git a/src/py/flwr/server/superlink/state/in_memory_state.py b/src/py/flwr/server/superlink/state/in_memory_state.py
index f8ae5a7e95b7..2c4519d8c148 100644
--- a/src/py/flwr/server/superlink/state/in_memory_state.py
+++ b/src/py/flwr/server/superlink/state/in_memory_state.py
@@ -116,6 +116,7 @@ def get_task_ins(
         # Return TaskIns
         return task_ins_list
 
+    # pylint: disable=R0911
     def store_task_res(self, task_res: TaskRes) -> Optional[UUID]:
         """Store one TaskRes."""
         # Validate task
@@ -129,6 +130,17 @@ def store_task_res(self, task_res: TaskRes) -> Optional[UUID]:
             task_ins_id = task_res.task.ancestry[0]
             task_ins = self.task_ins_store.get(UUID(task_ins_id))
 
+            # Ensure that the consumer_id of taskIns matches the producer_id of taskRes.
+            if (
+                task_ins
+                and task_res
+                and not (
+                    task_ins.task.consumer.anonymous or task_res.task.producer.anonymous
+                )
+                and task_ins.task.consumer.node_id != task_res.task.producer.node_id
+            ):
+                return None
+
             if task_ins is None:
                 log(ERROR, "TaskIns with task_id %s does not exist.", task_ins_id)
                 return None
diff --git a/src/py/flwr/server/superlink/state/sqlite_state.py b/src/py/flwr/server/superlink/state/sqlite_state.py
index 502b1e2461b2..73c121b01b4b 100644
--- a/src/py/flwr/server/superlink/state/sqlite_state.py
+++ b/src/py/flwr/server/superlink/state/sqlite_state.py
@@ -390,6 +390,16 @@ def store_task_res(self, task_res: TaskRes) -> Optional[UUID]:
             )
             return None
 
+        # Ensure that the consumer_id of taskIns matches the producer_id of taskRes.
+        if (
+            task_ins
+            and task_res
+            and not (task_ins["consumer_anonymous"] or task_res.task.producer.anonymous)
+            and convert_sint64_to_uint64(task_ins["consumer_node_id"])
+            != task_res.task.producer.node_id
+        ):
+            return None
+
         # Fail if the TaskRes TTL exceeds the
         # expiration time of the TaskIns it replies to.
         # Condition: TaskIns.created_at + TaskIns.ttl ≥
diff --git a/src/py/flwr/server/superlink/state/state_test.py b/src/py/flwr/server/superlink/state/state_test.py
index 2a5eab30b4b7..c3e0ac70d567 100644
--- a/src/py/flwr/server/superlink/state/state_test.py
+++ b/src/py/flwr/server/superlink/state/state_test.py
@@ -13,7 +13,7 @@
 # limitations under the License.
 # ==============================================================================
 """Tests all state implemenations have to conform to."""
-# pylint: disable=invalid-name, disable=R0904,R0913
+# pylint: disable=invalid-name, too-many-lines, R0904, R0913
 
 import tempfile
 import time
@@ -149,7 +149,7 @@ def test_store_and_delete_tasks(self) -> None:
 
         # Insert one TaskRes and retrive it to mark it as delivered
         task_res_0 = create_task_res(
-            producer_node_id=100,
+            producer_node_id=consumer_node_id,
             anonymous=False,
             ancestry=[str(task_id_0)],
             run_id=run_id,
@@ -160,7 +160,7 @@ def test_store_and_delete_tasks(self) -> None:
 
         # Insert one TaskRes, but don't retrive it
         task_res_1: TaskRes = create_task_res(
-            producer_node_id=100,
+            producer_node_id=consumer_node_id,
             anonymous=False,
             ancestry=[str(task_id_1)],
             run_id=run_id,
@@ -662,7 +662,7 @@ def test_node_unavailable_error(self) -> None:
 
         # Create and store TaskRes
         task_res_0 = create_task_res(
-            producer_node_id=100,
+            producer_node_id=node_id_0,
             anonymous=False,
             ancestry=[str(task_id_0)],
             run_id=run_id,
@@ -871,6 +871,32 @@ def test_get_task_res_return_if_not_expired(self) -> None:
             # Assert
             assert len(task_res_list) != 0
 
+    def test_store_task_res_fail_if_consumer_producer_id_mismatch(self) -> None:
+        """Test store_task_res to fail if there is a mismatch between the
+        consumer_node_id of taskIns and the producer_node_id of taskRes."""
+        # Prepare
+        consumer_node_id = 1
+        state = self.state_factory()
+        run_id = state.create_run(None, None, "9f86d08", {})
+        task_ins = create_task_ins(
+            consumer_node_id=consumer_node_id, anonymous=False, run_id=run_id
+        )
+
+        task_id = state.store_task_ins(task_ins=task_ins)
+
+        task_res = create_task_res(
+            producer_node_id=100,  # different than consumer_node_id
+            anonymous=False,
+            ancestry=[str(task_id)],
+            run_id=run_id,
+        )
+
+        # Execute
+        task_res_uuid = state.store_task_res(task_res=task_res)
+
+        # Assert
+        assert task_res_uuid is None
+
 
 def create_task_ins(
     consumer_node_id: int,