From 21967766b0694065b8fe95bcbc112ce8b257536b Mon Sep 17 00:00:00 2001
From: Felipe Knorr Kuhn <git@knorrium.info>
Date: Tue, 3 Mar 2026 19:16:44 -0800
Subject: [PATCH 1/3] Fix electrum address validation

---
 backend/src/api/bitcoin/bitcoin.routes.ts | 12 ++++++++++++
 backend/src/api/bitcoin/electrum-api.ts   | 22 +++-------------------
 2 files changed, 15 insertions(+), 19 deletions(-)

diff --git a/backend/src/api/bitcoin/bitcoin.routes.ts b/backend/src/api/bitcoin/bitcoin.routes.ts
index fafcfdbcd..1ae865701 100644
--- a/backend/src/api/bitcoin/bitcoin.routes.ts
+++ b/backend/src/api/bitcoin/bitcoin.routes.ts
@@ -664,6 +664,10 @@ class BitcoinRoutes {
       const addressData = await bitcoinApi.$getAddress(req.params.address);
       res.json(addressData);
     } catch (e) {
+      if (e instanceof Error && e.message === 'Invalid Bitcoin address') {
+        handleError(req, res, 400, e.message);
+        return;
+      }
       if (e instanceof Error && e.message && (e.message.indexOf('too long') > 0 || e.message.indexOf('confirmed status') > 0)) {
         handleError(req, res, 413, e.message);
         return;
@@ -690,6 +694,10 @@ class BitcoinRoutes {
       const transactions = await bitcoinApi.$getAddressTransactions(req.params.address, lastTxId);
       res.json(transactions);
     } catch (e) {
+      if (e instanceof Error && e.message === 'Invalid Bitcoin address') {
+        handleError(req, res, 400, e.message);
+        return;
+      }
       if (e instanceof Error && e.message && (e.message.indexOf('too long') > 0 || e.message.indexOf('confirmed status') > 0)) {
         handleError(req, res, 413, e.message);
         return;
@@ -712,6 +720,10 @@ class BitcoinRoutes {
       const addressData = await bitcoinApi.$getAddressUtxos(req.params.address);
       res.json(addressData);
     } catch (e) {
+      if (e instanceof Error && e.message === 'Invalid Bitcoin address') {
+        handleError(req, res, 400, e.message);
+        return;
+      }
       if (e instanceof Error && e.message && (e.message.indexOf('too long') > 0 || e.message.indexOf('confirmed status') > 0)) {
         handleError(req, res, 413, e.message);
         return;
diff --git a/backend/src/api/bitcoin/electrum-api.ts b/backend/src/api/bitcoin/electrum-api.ts
index aa9765420..bf9a28c5d 100644
--- a/backend/src/api/bitcoin/electrum-api.ts
+++ b/backend/src/api/bitcoin/electrum-api.ts
@@ -44,23 +44,7 @@ class BitcoindElectrsApi extends BitcoinApi implements AbstractBitcoinApi {
   async $getAddress(address: string): Promise<IEsploraApi.Address> {
     const addressInfo = await this.bitcoindClient.validateAddress(address);
     if (!addressInfo || !addressInfo.isvalid) {
-      return ({
-        'address': address,
-        'chain_stats': {
-          'funded_txo_count': 0,
-          'funded_txo_sum': 0,
-          'spent_txo_count': 0,
-          'spent_txo_sum': 0,
-          'tx_count': 0
-        },
-        'mempool_stats': {
-          'funded_txo_count': 0,
-          'funded_txo_sum': 0,
-          'spent_txo_count': 0,
-          'spent_txo_sum': 0,
-          'tx_count': 0
-        }
-      });
+      throw new Error('Invalid Bitcoin address');
     }
 
     try {
@@ -96,7 +80,7 @@ class BitcoindElectrsApi extends BitcoinApi implements AbstractBitcoinApi {
   async $getAddressTransactions(address: string, lastSeenTxId: string): Promise<IEsploraApi.Transaction[]> {
     const addressInfo = await this.bitcoindClient.validateAddress(address);
     if (!addressInfo || !addressInfo.isvalid) {
-      return [];
+      throw new Error('Invalid Bitcoin address');
     }
 
     try {
@@ -166,7 +150,7 @@ class BitcoindElectrsApi extends BitcoinApi implements AbstractBitcoinApi {
   async $getAddressUtxos(address: string): Promise<IEsploraApi.UTXO[]> {
     const addressInfo = await this.bitcoindClient.validateAddress(address);
     if (!addressInfo || !addressInfo.isvalid) {
-      return [];
+      throw new Error('Invalid Bitcoin address');
     }
     const scripthash = this.encodeScriptHash(addressInfo.scriptPubKey);
     return this.$getScriptHashUtxos(scripthash);

From 18e378f73a588c2f6f9759d548ccc5341d098856 Mon Sep 17 00:00:00 2001
From: Felipe Knorr Kuhn <git@knorrium.info>
Date: Tue, 3 Mar 2026 19:56:58 -0800
Subject: [PATCH 2/3] Don't send the error as json

---
 backend/src/api/bitcoin/bitcoin.routes.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/backend/src/api/bitcoin/bitcoin.routes.ts b/backend/src/api/bitcoin/bitcoin.routes.ts
index 1ae865701..237a7caec 100644
--- a/backend/src/api/bitcoin/bitcoin.routes.ts
+++ b/backend/src/api/bitcoin/bitcoin.routes.ts
@@ -665,7 +665,7 @@ class BitcoinRoutes {
       res.json(addressData);
     } catch (e) {
       if (e instanceof Error && e.message === 'Invalid Bitcoin address') {
-        handleError(req, res, 400, e.message);
+        res.status(400).send(e.message);
         return;
       }
       if (e instanceof Error && e.message && (e.message.indexOf('too long') > 0 || e.message.indexOf('confirmed status') > 0)) {
@@ -695,7 +695,7 @@ class BitcoinRoutes {
       res.json(transactions);
     } catch (e) {
       if (e instanceof Error && e.message === 'Invalid Bitcoin address') {
-        handleError(req, res, 400, e.message);
+        res.status(400).send(e.message);
         return;
       }
       if (e instanceof Error && e.message && (e.message.indexOf('too long') > 0 || e.message.indexOf('confirmed status') > 0)) {
@@ -721,7 +721,7 @@ class BitcoinRoutes {
       res.json(addressData);
     } catch (e) {
       if (e instanceof Error && e.message === 'Invalid Bitcoin address') {
-        handleError(req, res, 400, e.message);
+        res.status(400).send(e.message);
         return;
       }
       if (e instanceof Error && e.message && (e.message.indexOf('too long') > 0 || e.message.indexOf('confirmed status') > 0)) {

From c537a3f2544991fef2a6ce9603482920cfb4d938 Mon Sep 17 00:00:00 2001
From: Felipe Knorr Kuhn <git@knorrium.info>
Date: Tue, 3 Mar 2026 20:44:39 -0800
Subject: [PATCH 3/3] Do not send user to mempool.space on 400 errors

---
 frontend/src/app/components/address/address.component.html | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/frontend/src/app/components/address/address.component.html b/frontend/src/app/components/address/address.component.html
index b0d4c73da..0a2b0e2ed 100644
--- a/frontend/src/app/components/address/address.component.html
+++ b/frontend/src/app/components/address/address.component.html
@@ -249,11 +249,6 @@
           <br><br>
           Consider viewing this address on the official Mempool website instead:
         </ng-container>
-        } @else if (!officialMempoolSpace) {
-          <br>
-          Consider viewing this address on the official Mempool website instead:
-        }
-        @if (!officialMempoolSpace) {
           <br>
           <a href="https://mempool.space/address/{{ addressString }}" target="_blank">https://mempool.space/address/{{ addressString }}</a>
           <br>