diff --git a/docs/development/routing-design.md b/docs/development/routing-design.md
index aafc8251..a8c613be 100644
--- a/docs/development/routing-design.md
+++ b/docs/development/routing-design.md
@@ -70,7 +70,7 @@ state and the remaining validation work.
 | Surface | Current implementation | Target status |
 | --- | --- | --- |
 | Queue concrete route depth | Rejects trailing segments | Aligned |
-| Lease concrete route depth | Uses the first three segments and tolerates a trailing suffix | Gap: reject trailing segments |
+| Lease concrete route depth | Rejects trailing segments | Aligned |
 | Stream selector classification | All eight literal/`*` kinds and two aliases | Aligned |
 | Resource, area, and realm reads | Dedicated offset spaces and visibility frontiers | Aligned |
 | Global and global-filter reads | Direct family-global pages in assigned commit order | Aligned |
diff --git a/src/api/runtime_ingress/domain_frame_dispatcher.rs b/src/api/runtime_ingress/domain_frame_dispatcher.rs
index 56978adf..c4d67d8e 100644
--- a/src/api/runtime_ingress/domain_frame_dispatcher.rs
+++ b/src/api/runtime_ingress/domain_frame_dispatcher.rs
@@ -722,18 +722,18 @@ impl DomainFrameDispatcher<'_> {
                         "RPC request parse failed",
                     );
                 }
-                // Domain validation owns Lease observation selector errors:
-                // SUBSCRIBE/UNSUBSCRIBE return 5010 and LIST returns 5012,
-                // including on auth-required brokers. Dispatching these
-                // malformed selectors is safe because the Lease sink compiles
-                // and rejects them before retaining subscription state or
-                // inspecting inventory. Other auth-required domains keep the
-                // fail-closed behavior below.
-                let lease_observation_validation = matches!(
+                // Domain validation owns malformed Lease request errors:
+                // exact operations return 5008, SUBSCRIBE/UNSUBSCRIBE return
+                // 5010, and LIST returns 5012, including on auth-required
+                // brokers. Dispatching these malformed routes is safe because
+                // the Lease decoder rejects them before ownership, retained
+                // subscription state, or inventory can be touched. Other
+                // auth-required domains keep the fail-closed behavior below.
+                let lease_request_validation = matches!(
                     (dispatch.domain, dispatch.msg_type.as_u16()),
-                    (DispatchDomain::Lease, 407 | 408 | 410)
+                    (DispatchDomain::Lease, 400..=403 | 407 | 408 | 410)
                 );
-                if lease_observation_validation
+                if lease_request_validation
                     || (!self.ingress.auth_required
                         && is_subscription_registration_message(
                             dispatch.domain,
diff --git a/src/api/runtime_ingress/tests/authorization_routes_lease.rs b/src/api/runtime_ingress/tests/authorization_routes_lease.rs
index b4c62b20..16237b59 100644
--- a/src/api/runtime_ingress/tests/authorization_routes_lease.rs
+++ b/src/api/runtime_ingress/tests/authorization_routes_lease.rs
@@ -105,6 +105,88 @@ async fn malformed_authenticated_lease_observation(msg_type: u16) -> (IngressDec
     )
 }
 
+async fn malformed_authenticated_lease_operation(
+    msg_type: u16,
+    payload: Bytes,
+) -> (IngressDecision, u16) {
+    let family = RouteFamily::new(1);
+    let session_id = 700 + u64::from(msg_type);
+    let router = Arc::new(crate::runtime::Router::new());
+    let lease_sink = Arc::new(crate::domains::lease::sink::LeaseDomainSink::new(
+        router.clone(),
+        crate::control::admin::read_model::AdminReadModel::new(),
+    ));
+    let inbox_mailbox = Arc::new(Mailbox::new(8));
+    router.register_domain_pattern("lease", lease_sink);
+    router.register(
+        RouteAddress::new(family, Route::new(format!("inbox://session/{session_id}"))),
+        inbox_mailbox.clone(),
+    );
+    let ingress = runtime_ingress_with_jwks_auth().with_router(router);
+    let session =
+        make_authenticated_session_info(session_id, TransportKind::Tcp, family, &["lease://**#*"]);
+    ingress.on_open(session).await.unwrap();
+
+    let decision = ingress
+        .on_frame(
+            session_id,
+            ChannelId::Lease,
+            MessageType::new(msg_type),
+            payload,
+        )
+        .await;
+    let response = tokio::time::timeout(std::time::Duration::from_secs(1), async {
+        loop {
+            if !inbox_mailbox.receiver().is_empty() {
+                break receive_frame(&inbox_mailbox, "typed malformed Lease operation response");
+            }
+            tokio::time::sleep(std::time::Duration::from_millis(1)).await;
+        }
+    })
+    .await
+    .expect("typed malformed Lease operation response");
+    (
+        decision,
+        decode_domain_error_code(response.payload.as_ref()),
+    )
+}
+
+#[tokio::test]
+async fn should_return_typed_error_for_authenticated_malformed_lease_operations() {
+    // Arrange
+    let malformed = "lease://acme/locks/resource/extra";
+    let mut renew = PayloadEncoder::new();
+    renew.put_string(malformed);
+    renew.put_string("owner");
+    renew.put_u64(1);
+    renew.put_u64(30);
+    let mut release = PayloadEncoder::new();
+    release.put_string(malformed);
+    release.put_string("owner");
+    release.put_u64(1);
+    let mut query = PayloadEncoder::new();
+    query.put_string(malformed);
+    let requests = [
+        (400, encode_lease_acquire(malformed, "owner", 30)),
+        (401, Bytes::from(renew.finish())),
+        (402, Bytes::from(release.finish())),
+        (403, Bytes::from(query.finish())),
+    ];
+
+    for (msg_type, payload) in requests {
+        // Act
+        let (decision, code) = malformed_authenticated_lease_operation(msg_type, payload).await;
+
+        // Assert
+        assert_eq!(decision, IngressDecision::Accept);
+        assert_eq!(
+            code,
+            crate::protocol::error_codes::lease::ERR_BAD_REQUEST,
+            "message type {msg_type}"
+        );
+    }
+}
+
 #[tokio::test]
 async fn should_return_typed_error_for_authenticated_malformed_lease_subscribe() {
     // Arrange
diff --git a/src/domains/lease/sink/ingress.rs b/src/domains/lease/sink/ingress.rs
index 4d02d6b0..82764494 100644
--- a/src/domains/lease/sink/ingress.rs
+++ b/src/domains/lease/sink/ingress.rs
@@ -316,7 +316,7 @@ impl LeaseDomainRuntime<'_> {
                         channel: meta.channel,
                         route_family: meta.route_family,
                     }),
-                    None => LeaseResponse::NotFound,
+                    None => Self::error_response("invalid lease route"),
                 }
             }
             LeaseMessage::Extend {
@@ -332,7 +332,7 @@ impl LeaseDomainRuntime<'_> {
                     *fencing_token,
                     *ttl_secs,
                 ),
-                None => LeaseResponse::NotFound,
+                None => Self::error_response("invalid lease route"),
             },
             LeaseMessage::Release {
                 family_id,
@@ -345,12 +345,12 @@ impl LeaseDomainRuntime<'_> {
                     scoped_owner_id.expect("release owner must be scoped before dispatch"),
                     *fencing_token,
                 ),
-                None => LeaseResponse::NotFound,
+                None => Self::error_response("invalid lease route"),
             },
             LeaseMessage::Query { family_id, route } => {
                 match LeaseKey::from_route(*family_id, route) {
                     Some(key) => self.handle_query(&key),
-                    None => LeaseResponse::NotFound,
+                    None => Self::error_response("invalid lease route"),
                 }
             }
             LeaseMessage::List {