diff --git a/vllm/distributed/kv_transfer/kv_connector/v1/moriio/moriio_common.py b/vllm/distributed/kv_transfer/kv_connector/v1/moriio/moriio_common.py
index b843c5b59308..1a743b35d1e9 100644
--- a/vllm/distributed/kv_transfer/kv_connector/v1/moriio/moriio_common.py
+++ b/vllm/distributed/kv_transfer/kv_connector/v1/moriio/moriio_common.py
@@ -347,17 +347,51 @@ def add_new_req(
         transfer_id = kv_transfer_params["transfer_id"]
 
         # Parse host/ports from the request_id. The router embeds both zmq_addresses
-        # in the request_id
-        peer_zmq = get_peer_zmq_from_request_id(request_id, is_producer=write_mode)
-        remote_host, remote_handshake_port, remote_notify_port = (
-            parse_moriio_zmq_address(peer_zmq)
-        )
-
+        # in the request_id. Some cleanup-path requests (e.g. those that hit the
+        # external prefix cache and take the "aborted before scheduling" branch
+        # in `request_finished`) surface a short internal request_id without
+        # the proxy's `___prefill_addr_...` prefix; `get_peer_zmq_from_request_id`
+        # raises ValueError on those. Fall back to `kv_transfer_params.remote_hosts`
+        # (proxy already forwards it for multi-node TP) and MoRIIO's default
+        # well-known ports, which match the kv_connector_extra_config the runner
+        # scripts pass on every container. Only the request_id parse path is
+        # affected; once we have a valid host/port triple we proceed as before.
+        try:
+            peer_zmq = get_peer_zmq_from_request_id(request_id, is_producer=write_mode)
+            remote_host, remote_handshake_port, remote_notify_port = (
+                parse_moriio_zmq_address(peer_zmq)
+            )
+        except ValueError:
+            # Normalize remote_hosts: callers may pass a list (per-rank host
+            # vector from the proxy) or a single host string from older
+            # proxy versions. A bare string would silently slice into "1."
+            # for "172.30.0.1" if we just did remote_hosts[0].
+            remote_hosts_raw = kv_transfer_params.get("remote_hosts") or []
+            if isinstance(remote_hosts_raw, str):
+                remote_hosts = [remote_hosts_raw] if remote_hosts_raw else []
+            else:
+                remote_hosts = list(remote_hosts_raw)
+            if not remote_hosts:
+                raise ValueError(
+                    f"MoRIIO add_new_req: could not resolve peer host/ports "
+                    f"for {request_id!r}; neither request_id parse nor "
+                    f"kv_transfer_params.remote_hosts provided them"
+                ) from None
+            remote_host = remote_hosts[0]
+            remote_handshake_port = int(MoRIIOConstants.DEFAULT_HANDSHAKE_PORT)
+            remote_notify_port = int(MoRIIOConstants.DEFAULT_NOTIFY_PORT)
+
+        # Cleanup-path requests (the same "aborted before scheduling" branch
+        # that surfaces a short request_id) can also omit remote_block_ids
+        # and remote_engine_id. Use .get() defaults so we don't crash the
+        # same EngineCore the request_id fallback above is meant to keep
+        # alive — an empty block list is the correct no-op for an aborted
+        # request.
         _req = ReqMeta(
             transfer_id=transfer_id,
             local_block_ids=local_block_ids,
-            remote_block_ids=kv_transfer_params["remote_block_ids"],
-            remote_engine_id=kv_transfer_params["remote_engine_id"],
+            remote_block_ids=kv_transfer_params.get("remote_block_ids", []),
+            remote_engine_id=kv_transfer_params.get("remote_engine_id", ""),
             remote_host=remote_host,
             remote_port=remote_handshake_port,
             remote_handshake_port=remote_handshake_port,