diff --git a/routes/openclaw_bot_routes.py b/routes/openclaw_bot_routes.py
index 3f13f18..ed97a29 100644
--- a/routes/openclaw_bot_routes.py
+++ b/routes/openclaw_bot_routes.py
@@ -93,6 +93,25 @@ ALLOWED_USERS: set = (
     if _allowed_users_raw.strip() else set()
 )
 
+# ── fail-closed 統一授權檢查 ───────────────────────────────────
+# 規則（任一滿足即通過，否則一律拒絕）：
+#   1. group/supergroup 且 chat_id == ALLOWED_GROUP
+#   2. private 且 user_id ∈ ALLOWED_USERS（env 未設 → 空 set → 全拒）
+# channel / 未知 chat_type / 缺欄位 → 拒絕
+# 修補 C3：callback handler 原本只擋 group/supergroup 不匹配，private 完全放行；
+#          message handler `if ALLOWED_USERS and ...` 空 set 時整段失效。
+def _is_authorized(chat_type: str, chat_id, user_id) -> bool:
+    try:
+        cid = int(chat_id) if chat_id is not None else None
+        uid = int(user_id) if user_id is not None else None
+    except (TypeError, ValueError):
+        return False
+    if chat_type in ('group', 'supergroup'):
+        return cid == ALLOWED_GROUP
+    if chat_type == 'private':
+        return uid is not None and uid in ALLOWED_USERS
+    return False
+
 # ── 速率限制（每用戶每分鐘最多 30 次 AI 呼叫）──────────────────
 import time as _time_mod
 _rate_tracker: dict = {}   # {user_id: [timestamp, ...]}
@@ -5169,11 +5188,16 @@ def telegram_webhook():
             data    = cq.get('data', '')
             chat_id = cq['message']['chat']['id']
             chat_type = cq['message']['chat'].get('type', '')
+            cq_from_id = (cq.get('from') or {}).get('id')
             sys_log.info(f'[OpenClawBot] CB: chat={chat_id} type={chat_type} data={data} allowed={ALLOWED_GROUP}')
 
-            if chat_type in ('group', 'supergroup') and chat_id != ALLOWED_GROUP:
+            # fail-closed：未授權一律安靜拒絕（關閉 loading，不回任何訊息避免偵察）
+            if not _is_authorized(chat_type, chat_id, cq_from_id):
+                sys_log.warning(
+                    f'[OpenClawBot] CB rejected: chat={chat_id} type={chat_type} user={cq_from_id}'
+                )
                 answer_callback(cq_id)
-                return jsonify({'ok': True})
+                return jsonify({'ok': False, 'error': 'forbidden'}), 403
 
             answer_callback(cq_id)
             send_typing(chat_id)
@@ -5226,20 +5250,21 @@ def telegram_webhook():
         text_raw  = (msg.get('text') or '').strip()
         msg_id    = msg.get('message_id')
 
+        # fail-closed 統一授權檢查（覆蓋 group/supergroup/private/channel/unknown）
+        _uid = (msg.get('from') or {}).get('id')
+        if not _is_authorized(chat_type, chat_id, _uid):
+            sys_log.warning(
+                f'[OpenClawBot] MSG rejected: chat={chat_id} type={chat_type} user={_uid}'
+            )
+            # 靜默拒絕：不回 Telegram 訊息（避免陌生人偵察 bot 存在與白名單機制）
+            return jsonify({'ok': False, 'error': 'forbidden'}), 403
+
         if chat_type in ('group', 'supergroup'):
-            if chat_id != ALLOWED_GROUP:
-                return jsonify({'ok': True})
             # 移除 @mention（不強制要求，但如有則移除）
             question = text_raw.replace(BOT_USERNAME, '').strip()
-        elif chat_type == 'private':
-            # 私訊存取控制 — 只允許白名單用戶
-            _uid = msg.get('from', {}).get('id', 0)
-            if ALLOWED_USERS and _uid not in ALLOWED_USERS:
-                send_message(chat_id, "⚠️ 此 Bot 僅限授權用戶使用，請聯絡管理員。", msg_id)
-                return jsonify({'ok': True})
-            question = text_raw
         else:
-            return jsonify({'ok': True})
+            # 已通過授權的 private chat
+            question = text_raw
 
         # ── 圖片訊息：Gemini Vision 商品辨識 ─────────────────────
         if not question and msg.get('photo'):