diff --git a/api/add_comment.php b/api/add_comment.php
index 06538b7..6fecce9 100644
--- a/api/add_comment.php
+++ b/api/add_comment.php
@@ -177,9 +177,16 @@ try {
         $ticketTitle   = $ticket['title'] ?? "Ticket #{$ticketId}";
         $ticketVisibility = $ticket['visibility'] ?? 'public';
 
-        // @mention notifications — resolve usernames → Matrix IDs via Synapse Admin API
-        if (!empty($mentionedUsers)) {
-            $mentionedUsernames = array_column($mentionedUsers, 'username');
+        // @mention notifications — resolve usernames → Matrix IDs via Synapse Admin API.
+        // Only notify mentioned users who actually have access to this ticket;
+        // otherwise a mention would DM them the ticket's title and comment text
+        // even though canUserAccessTicket() would deny them the ticket itself.
+        $accessibleMentionedUsers = array_filter(
+            $mentionedUsers,
+            fn($u) => $ticketModel->canUserAccessTicket($ticket, $u)
+        );
+        if (!empty($accessibleMentionedUsers)) {
+            $mentionedUsernames = array_column($accessibleMentionedUsers, 'username');
             $mentionedMatrixIds = SynapseHelper::resolveUsernames($mentionedUsernames);
             if (!empty($mentionedMatrixIds)) {
                 NotificationHelper::sendMentionNotification($ticketId, $ticketTitle, $commentText, $authorDisplay, $mentionedMatrixIds);
diff --git a/models/CommentModel.php b/models/CommentModel.php
index 419f26b..57b816e 100644
--- a/models/CommentModel.php
+++ b/models/CommentModel.php
@@ -38,7 +38,7 @@ class CommentModel
         }
 
         $placeholders = str_repeat('?,', count($usernames) - 1) . '?';
-        $sql = "SELECT user_id, username, display_name FROM users WHERE username IN ($placeholders)";
+        $sql = "SELECT user_id, username, display_name, is_admin, `groups` FROM users WHERE username IN ($placeholders)";
         $stmt = $this->conn->prepare($sql);
 
         $types = str_repeat('s', count($usernames));