diff --git a/inc/mod/pages.php b/inc/mod/pages.php
index 219141b2..2d5b87ab 100644
--- a/inc/mod/pages.php
+++ b/inc/mod/pages.php
@@ -19,6 +19,16 @@ function _link_or_copy_factory(Context $ctx): callable {
     };
 }
 
+function _trim_str_param(array $arr, string $key): ?string {
+    if (isset($arr[$key])) {
+        $trimmed = \trim($arr[$key]);
+        if (!empty($trimmed)) {
+            return $trimmed;
+        }
+    }
+    return null;
+}
+
 function mod_page($title, $template, $args, $subtitle = false) {
     global $config, $mod;
 
@@ -1113,14 +1123,19 @@ function mod_ban(Context $ctx) {
     if (!hasPermission($config['mod']['ban']))
         error($config['error']['noaccess']);
 
-    if (!isset($_POST['ip'], $_POST['reason'], $_POST['length'], $_POST['board'])) {
+    $ip = _trim_str_param($_POST, 'ip' );
+    $reason = _trim_str_param($_POST, 'reason');
+    $length = _trim_str_param($_POST, 'length');
+    $board = _trim_str_param($_POST, 'board');
+
+    if (!isset($ip, $reason, $length, $board)) {
         mod_page(_('New ban'), 'mod/ban_form.html', array('token' => make_secure_link_token('ban')));
         return;
     }
 
     require_once 'inc/mod/ban.php';
 
-    Bans::new_ban($_POST['ip'], $_POST['reason'], $_POST['length'], $_POST['board'] == '*' ? false : $_POST['board']);
+    Bans::new_ban($ip, $reason, $length, $board == '*' ? false : $board);
 
     if (isset($_POST['redirect']))
         header('Location: ' . $_POST['redirect'], true, $config['redirect_http']);
@@ -1967,25 +1982,41 @@ function mod_ban_post(Context $ctx, $board, $delete, $post, $token = false) {
     if (isset($_POST['new_ban'], $_POST['reason'], $_POST['length'], $_POST['board'])) {
         require_once 'inc/mod/ban.php';
 
-        if (isset($_POST['ip']))
-            $ip = $_POST['ip'];
+        if (isset($_POST['ip'])) {
+            $ip_trim = \trim($_POST['ip']);
+            if (!empty($ip_trim)) {
+                $ip = $ip_trim;
+            }
+        }
 
-        Bans::new_ban($_POST['ip'], $_POST['reason'], $_POST['length'], $_POST['board'] == '*' ? false : $_POST['board'],
+        $target_ip = \trim($_POST['ip']);
+        $reason = \trim($_POST['reason']);
+        $length = \trim($_POST['length']);
+        $target_board = \trim($_POST['board']);
+
+        Bans::new_ban($target_ip, $reason, $length, $target_board == '*' ? false : $target_board,
             false, $config['ban_show_post'] ? $_post : false);
 
-        if (isset($_POST['public_message'], $_POST['message'])) {
+        $message = _trim_str_param($_POST, 'message');
+        $public_message = _trim_str_param($_POST, 'public_message');
+
+        if (isset($public_message, $message)) {
             // public ban message
-            $length_english = Bans::parse_time($_POST['length']) ? 'for ' . until(Bans::parse_time($_POST['length'])) : 'permanently';
-            $_POST['message'] = preg_replace('/[\r\n]/', '', $_POST['message']);
-            $_POST['message'] = str_replace('%length%', $length_english, $_POST['message']);
-            $_POST['message'] = str_replace('%LENGTH%', strtoupper($length_english), $_POST['message']);
+            $length_parsed = Bans::parse_time($length);
+            $length_english = $length_parsed ? 'for ' . until($length_parsed) : 'permanently';
+
+            $message = \trim($_POST['message']);
+            $message = \preg_replace('/[\r\n]/', '', $message);
+            $message = \str_replace('%length%', $length_english, $message);
+            $message = \str_replace('%LENGTH%', \strtoupper($length_english), $message);
+
             $query = prepare(sprintf('UPDATE ``posts_%s`` SET `body_nomarkup` = CONCAT(`body_nomarkup`, :body_nomarkup) WHERE `id` = :id', $board));
             $query->bindValue(':id', $post);
-            $query->bindValue(':body_nomarkup', sprintf("\n<tinyboard ban message>%s</tinyboard>", utf8tohtml($_POST['message'])));
+            $query->bindValue(':body_nomarkup', sprintf("\n<tinyboard ban message>%s</tinyboard>", utf8tohtml($message)));
             $query->execute() or error(db_error($query));
             rebuildPost($post);
 
-            modLog("Attached a public ban message to post #{$post}: " . utf8tohtml($_POST['message']));
+            modLog("Attached a public ban message to post #{$post}: " . utf8tohtml($message));
             buildThread($thread ? $thread : $post);
             buildIndex();
         } elseif (isset($_POST['delete']) && (int) $_POST['delete']) {
@@ -2083,19 +2114,25 @@ function mod_warning_post(Context $ctx, $board, $post, $token = false) {
     $ip = $_post['ip'];
 
     if (isset($_POST['new_warning'])) {
-        if (isset($_POST['ip']))
-            $ip = $_POST['ip'];
+        if (isset($_POST['ip'])) {
+            $ip_trim = \trim($_POST['ip']);
+            if (!empty($ip_trim)) {
+                $ip = $ip_trim;
+            }
+        }
 
-        if (isset($_POST['public_message'], $_POST['message'])) {
+        $message = _trim_str_param($_POST, 'message');
+        $public_message = _trim_str_param($_POST, 'public_message');
+
+        if (isset($public_message, $message)) {
             // public warning message
-            $_POST['message'] = preg_replace('/[\r\n]/', '', $_POST['message']);
             $query = prepare(sprintf('UPDATE ``posts_%s`` SET `body_nomarkup` = CONCAT(`body_nomarkup`, :body_nomarkup) WHERE `id` = :id', $board));
             $query->bindValue(':id', $post);
-            $query->bindValue(':body_nomarkup', sprintf("\n<tinyboard warning message>%s</tinyboard>", utf8tohtml($_POST['message'])));
+            $query->bindValue(':body_nomarkup', sprintf("\n<tinyboard warning message>%s</tinyboard>", utf8tohtml($message)));
             $query->execute() or error(db_error($query));
             rebuildPost($post);
 
-            modLog("Attached a public warning message to post #{$post}: " . utf8tohtml($_POST['message']));
+            modLog("Attached a public warning message to post #{$post}: " . utf8tohtml($message));
             buildThread($thread ? $thread : $post);
             buildIndex();