diff --git a/contributors/emails/nyaruko@hermes b/contributors/emails/nyaruko@hermes
new file mode 100644
index 000000000000..430861e13081
--- /dev/null
+++ b/contributors/emails/nyaruko@hermes
@@ -0,0 +1 @@
+tsuk1nose
diff --git a/gateway/authz_mixin.py b/gateway/authz_mixin.py
index 7cd3dc1eb069..24910144d4ef 100644
--- a/gateway/authz_mixin.py
+++ b/gateway/authz_mixin.py
@@ -43,6 +43,21 @@ def _auth_env(name: str, default: str = "") -> str:
     return (os.getenv(name) or default).strip()
 
 
+def _coerce_allow_set(raw) -> set[str]:
+    """Parse allowlist values from config or env var into a set of strings.
+
+    Handles both list inputs (YAML sequences) and comma-separated string
+    inputs (env vars or scalar YAML values).  A scalar string is split on
+    commas so ``allow_from: "123,456"`` yields ``{"123", "456"}``, not
+    ``{"1", "2", "3", ",", ...}``.
+    """
+    if raw is None:
+        return set()
+    if isinstance(raw, list):
+        return {str(part).strip() for part in raw if str(part).strip()}
+    return {part.strip() for part in str(raw).split(",") if part.strip()}
+
+
 class GatewayAuthorizationMixin:
     """User/chat authorization methods for ``GatewayRunner``."""
 
@@ -369,7 +384,7 @@ class GatewayAuthorizationMixin:
                     extra = getattr(getattr(adapter, "config", None), "extra", None) or {}
                     adapter_group_allowed = extra.get("group_allowed_chats")
                     if adapter_group_allowed:
-                        allowed = {str(c).strip() for c in adapter_group_allowed if str(c).strip()}
+                        allowed = _coerce_allow_set(adapter_group_allowed)
                         if "*" in allowed or source.chat_id in allowed:
                             return True
             except Exception:
@@ -550,12 +565,12 @@ class GatewayAuthorizationMixin:
             adapter = self._adapter_for_source(source)
             if adapter is not None:
                 extra = getattr(getattr(adapter, "config", None), "extra", None) or {}
-                if source.chat_type in {"group", "forum"}:
+                if source.chat_type in {"group", "forum", "channel"}:
                     adapter_allow = extra.get("group_allow_from")
                 else:
                     adapter_allow = extra.get("allow_from")
                 if adapter_allow:
-                    allowed = {str(u).strip() for u in adapter_allow if str(u).strip()}
+                    allowed = _coerce_allow_set(adapter_allow)
                     if user_id in allowed or "*" in allowed:
                         return True
             # No allowlists configured -- check global allow-all flag
diff --git a/plugins/platforms/telegram/adapter.py b/plugins/platforms/telegram/adapter.py
index b4a46878e64e..05883c0e2ffe 100644
--- a/plugins/platforms/telegram/adapter.py
+++ b/plugins/platforms/telegram/adapter.py
@@ -250,6 +250,7 @@ import sys
 from pathlib import Path as _Path
 sys.path.insert(0, str(_Path(__file__).resolve().parents[3]))
 
+from gateway.authz_mixin import _coerce_allow_set
 from gateway.config import Platform, PlatformConfig
 from gateway.platforms.base import (
     BasePlatformAdapter,
@@ -1016,12 +1017,12 @@ class TelegramAdapter(BasePlatformAdapter):
         # Adapter-level allow_from / group_allow_from: when set, they are the
         # sole authority.  Group chats use group_allow_from; DMs use allow_from.
         chat_type = source.chat_type or ""
-        if chat_type in ("group", "forum"):
+        if chat_type in ("group", "forum", "channel"):
             adapter_allow_from = self.config.extra.get("group_allow_from")
         else:
             adapter_allow_from = self.config.extra.get("allow_from")
         if adapter_allow_from is not None:
-            allowed = {str(u).strip() for u in adapter_allow_from if str(u).strip()}
+            allowed = _coerce_allow_set(adapter_allow_from)
             return user_id in allowed or "*" in allowed
 
         # Test/custom injection only. The class method named
@@ -9410,7 +9411,7 @@ def _apply_yaml_config(yaml_cfg: dict, telegram_cfg: dict) -> dict | None:
         if isinstance(group_allowed_users, list):
             group_allowed_users = ",".join(str(v) for v in group_allowed_users)
         os.environ["TELEGRAM_GROUP_ALLOWED_USERS"] = str(group_allowed_users)
-    group_allowed_chats = telegram_cfg.get("group_allowed_chats")
+    group_allowed_chats = telegram_cfg.get("group_allowed_chats") or _telegram_extra.get("group_allowed_chats")
     if group_allowed_chats is not None and not os.getenv("TELEGRAM_GROUP_ALLOWED_CHATS"):
         if isinstance(group_allowed_chats, list):
             group_allowed_chats = ",".join(str(v) for v in group_allowed_chats)
diff --git a/tests/gateway/test_telegram_group_gating.py b/tests/gateway/test_telegram_group_gating.py
index 9f69132d86eb..1dc9a13a6f2d 100644
--- a/tests/gateway/test_telegram_group_gating.py
+++ b/tests/gateway/test_telegram_group_gating.py
@@ -346,7 +346,9 @@ def test_observed_group_context_preserves_slash_command_text_for_dispatch():
 
     assert attributed.text == "/new@hermes_bot"
     assert attributed.get_command() == "new"
-    assert attributed.source.user_id is None
+    # Commands preserve sender identity for slash-access control (#67816).
+    assert attributed.source.user_id == "111"
+    assert attributed.source.user_name == "Alice"
     assert "observed Telegram group context" in attributed.channel_prompt