diff --git a/haos-addon/config.yaml b/haos-addon/config.yaml
index 4e2c622..8ce8c8c 100644
--- a/haos-addon/config.yaml
+++ b/haos-addon/config.yaml
@@ -1,5 +1,5 @@
 name: Growatt ShineLAN-X
-version: "1.1.2"
+version: "1.1.3"
 slug: growatt_shinelan_x
 description: Growatt Wechselrichter via ShineLAN-X (NuttX Modbus TCP) - MQTT Discovery + Web UI
 url: https://gitea.bitfire.work/retr0/Growatt-Wechselrichter-HAOS
diff --git a/haos-addon/src/main.py b/haos-addon/src/main.py
index 1b46ff6..12f39e6 100644
--- a/haos-addon/src/main.py
+++ b/haos-addon/src/main.py
@@ -87,12 +87,18 @@ def _poll_loop(inv_cfg: Dict[str, Any], stop: threading.Event):
     inverter = INVERTERS.get(model_id, INVERTERS["MIC_1500_TL_X"])
     prefix = inv_cfg.get("mqtt_topic_prefix", f"growatt/{inv_id}")
     device_id = f"growatt_{inv_id}"
-    interval = max(5, int(inv_cfg.get("update_interval", 30)))
+    try:
+        interval = max(5, int(inv_cfg.get("update_interval", 30)))
+        port = int(inv_cfg.get("modbus_port", 502))
+        slave = int(inv_cfg.get("modbus_address", 1))
+    except (ValueError, TypeError) as e:
+        log.error("[%s] Ungültige Konfiguration: %s", inv_id, e)
+        return
 
     reader = ModbusReader(
         host=inv_cfg["modbus_ip"],
-        port=int(inv_cfg.get("modbus_port", 502)),
-        slave=int(inv_cfg.get("modbus_address", 1)),
+        port=port,
+        slave=slave,
     )
 
     with State.lock:
@@ -202,6 +208,19 @@ def api_get_inverters():
 @app.post("/api/inverters-config")
 def api_save_inverters():
     data = request.get_json(force=True) or []
+    if not isinstance(data, list):
+        return jsonify({"error": "invalid"}), 400
+    for inv in data:
+        if not isinstance(inv, dict):
+            return jsonify({"error": "invalid"}), 400
+        if inv.get("inverter_model") not in INVERTERS:
+            return jsonify({"error": f"unknown model: {inv.get('inverter_model')}"}), 400
+        port = inv.get("modbus_port", 502)
+        if not isinstance(port, int) or not (1 <= port <= 65535):
+            return jsonify({"error": "invalid port"}), 400
+        addr = inv.get("modbus_address", 1)
+        if not isinstance(addr, int) or not (1 <= addr <= 247):
+            return jsonify({"error": "invalid modbus address (1-247)"}), 400
     with State.lock:
         State.inverters_cfg = data
         save_config()
@@ -284,4 +303,4 @@ if __name__ == "__main__":
     _restart_all()
     port = int(os.environ.get("INGRESS_PORT", "8099"))
     log.info("Web UI startet auf Port %d", port)
-    app.run(host="0.0.0.0", port=port, threaded=True)
+    app.run(host="127.0.0.1", port=port, threaded=True)
diff --git a/haos-addon/src/web/index.html b/haos-addon/src/web/index.html
index 9fa910c..dfd91bd 100644
--- a/haos-addon/src/web/index.html
+++ b/haos-addon/src/web/index.html
@@ -221,6 +221,10 @@
 <div class="toast" id="toast"></div>
 
 <script>
+function esc(s) {
+  return String(s).replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;').replace(/"/g,'&quot;').replace(/'/g,'&#39;');
+}
+
 const DC_COLORS = {
   power: '#f0c040', voltage: '#58a6ff', current: '#ffa657',
   energy: '#3fb950', temperature: '#f85149', battery: '#bc8cff',
@@ -314,14 +318,14 @@ function renderLive(inverters) {
       const hist = (inv.history || {})[s.id] || [];
       return `<div class="sensor-card ${dcClass}">
         <div class="sensor-icon">${ICON_MAP[s.icon]||"📊"}</div>
-        <div class="sensor-name">${s.name}</div>
-        <div class="sensor-value">${display}<span class="sensor-unit">${s.unit}</span></div>
+        <div class="sensor-name">${esc(s.name)}</div>
+        <div class="sensor-value">${display}<span class="sensor-unit">${esc(s.unit)}</span></div>
         ${sparkline(hist, s.device_class)}
       </div>`;
     }).join("");
     return `<div class="inv-section">
       <div class="inv-header">
-        <div class="inv-title">${inv.name}</div>
+        <div class="inv-title">${esc(inv.name)}</div>
         <div class="inv-badge ${inv.modbus_ok ? "ok" : "err"}">${inv.modbus_ok ? "online" : "offline"}</div>
         <div class="info-chip" style="margin-left:auto;font-size:11px">⏱ ${ago} vor · ${inv.poll_count} Messungen</div>
       </div>
@@ -350,7 +354,7 @@ async function loadModels() {
   modelsList = await fetchJSON(api("api/inverter-models"));
   const sel = document.getElementById("modal-model");
   sel.innerHTML = Object.values(modelsList).map(m =>
-    `<option value="${m.id}">${m.name} (${m.sensor_count} Sensoren)</option>`
+    `<option value="${esc(m.id)}">${esc(m.name)} (${m.sensor_count} Sensoren)</option>`
   ).join("");
 }
 
@@ -362,13 +366,13 @@ function renderInverterList() {
       <div class="inv-card-header">
         <div class="inv-card-icon">☀️</div>
         <div class="inv-card-info">
-          <div class="inv-card-name">${inv.name || "Wechselrichter"}</div>
-          <div class="inv-card-model">${model.name || inv.inverter_model}</div>
+          <div class="inv-card-name">${esc(inv.name || "Wechselrichter")}</div>
+          <div class="inv-card-model">${esc(model.name || inv.inverter_model)}</div>
         </div>
       </div>
       <div class="inv-card-meta">
-        📡 ${inv.modbus_ip}:${inv.modbus_port || 502} · Slave ${inv.modbus_address || 1}<br>
-        📨 ${inv.mqtt_topic_prefix}<br>
+        📡 ${esc(inv.modbus_ip)}:${inv.modbus_port || 502} · Slave ${inv.modbus_address || 1}<br>
+        📨 ${esc(inv.mqtt_topic_prefix)}<br>
         ⏱ alle ${inv.update_interval || 30}s
       </div>
       <div class="inv-card-actions">