fix: Users without preview permission possibility of subscribe to public channel stream

.changeset/lemon-lions-learn.md

@@ -0,0 +1,5 @@
+---
+"@rocket.chat/meteor": patch
+---
+
+fixes the possibility of see new messages without being subscribed to a public channel.

apps/meteor/server/modules/notifications/notifications.module.ts

@@ -102,6 +102,7 @@ export class NotificationsModule {
 			}
 
 			const canAccess = await Authorization.canAccessRoom(room, { _id: this.userId || '' }, extraData);
+
 			if (!canAccess) {
 				// verify if can preview messages from public channels
 				if (room.t === 'c' && this.userId) {
@@ -110,6 +111,16 @@ export class NotificationsModule {
 				return false;
 			}
 
+			if (room.t === 'c' && this.userId) {
+				if (await Authorization.hasPermission(this.userId, 'preview-c-room')) {
+					const subscription = await Subscriptions.findOneByRoomIdAndUserId(room._id, this.userId);
+
+					return !!subscription;
+				}
+
+				return false;
+			}
+
 			return true;
 		});