From 5f5e40ac1462f72f86793fb4ad697165453e8b8d Mon Sep 17 00:00:00 2001
From: xg95 <77263687+xg95@users.noreply.github.com>
Date: Wed, 8 Jul 2026 12:07:15 +0800
Subject: [PATCH 1/2] poc

---
 contracts/message-transmitter-v2/src/test.rs | 38 ++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/contracts/message-transmitter-v2/src/test.rs b/contracts/message-transmitter-v2/src/test.rs
index 2b455f8..7b15aa0 100644
--- a/contracts/message-transmitter-v2/src/test.rs
+++ b/contracts/message-transmitter-v2/src/test.rs
@@ -971,6 +971,44 @@ fn test_receive_message_fails_with_nonce_already_used() {
     client.receive_message(&caller, &fixture.message, &fixture.attestation);
 }
 
+#[test]
+fn test_nonce_expiry_allows_message_replay() {
+    let ctx = setup_contract();
+    let client = ctx.client();
+    let caller = Address::generate(&ctx.env);
+
+    let _mock_handler_address = ctx.env.register(MockMessageHandler, ());
+    let fixture = fixture_valid_message(&ctx.env);
+
+    mock_receive_message_auth(
+        &ctx.env,
+        &ctx.contract_id,
+        &caller,
+        fixture.message.clone(),
+        fixture.attestation.clone(),
+    );
+    client.receive_message(&caller, &fixture.message, &fixture.attestation);
+
+    let nonce = MessageV2::get_nonce(&fixture.message).unwrap();
+    assert!(client.is_nonce_used(&nonce));
+
+    let nonce_key = storage::MessageTransmitterStorageKey::UsedNonce(nonce.clone());
+    ctx.env.as_contract(&ctx.contract_id, || {
+        ctx.env.storage().persistent().remove(&nonce_key);
+    });
+
+    assert!(!client.is_nonce_used(&nonce));
+
+    mock_receive_message_auth(
+        &ctx.env,
+        &ctx.contract_id,
+        &caller,
+        fixture.message.clone(),
+        fixture.attestation.clone(),
+    );
+    client.receive_message(&caller, &fixture.message, &fixture.attestation);
+}
+
 // =============================================================
 // Attestable Tests
 // =============================================================

From af4a4e7bc9794fa9d2f584ba2227357d2449b056 Mon Sep 17 00:00:00 2001
From: xg95 <77263687+xg95@users.noreply.github.com>
Date: Wed, 8 Jul 2026 13:13:53 +0800
Subject: [PATCH 2/2] fix

---
 contracts/message-transmitter-v2/src/test.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/contracts/message-transmitter-v2/src/test.rs b/contracts/message-transmitter-v2/src/test.rs
index 7b15aa0..dd929e5 100644
--- a/contracts/message-transmitter-v2/src/test.rs
+++ b/contracts/message-transmitter-v2/src/test.rs
@@ -16,6 +16,7 @@
  * limitations under the License.
  */
 use crate::contract::MessageTransmitterV2ContractInitParams;
+use crate::storage;
 use crate::test_utils::{
     create_test_message, fixture_invalid_destination_caller_message,
     fixture_invalid_destination_domain_message, fixture_invalid_version_message,