diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index 8a450ce934c..428daf8afb4 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -1,6 +1,7 @@
 
-Drupal 6.27-dev, xxxx-xx-xx (development release)
+Drupal 6.27, 2012-12-19
 ----------------------
+- Fixed security issues (multiple vulnerabilities), see SA-CORE-2012-004.
 
 Drupal 6.26, 2012-05-02
 ----------------------
diff --git a/includes/common.inc b/includes/common.inc
index 7d0bf853939..b86f2d2edc0 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -663,7 +663,7 @@ function drupal_error_handler($errno, $message, $filename, $line, $context) {
     return;
   }
 
-  if ($errno & (E_ALL ^ E_DEPRECATED)) {
+  if ($errno & (E_ALL ^ E_DEPRECATED ^ E_NOTICE)) {
     $types = array(1 => 'error', 2 => 'warning', 4 => 'parse error', 8 => 'notice', 16 => 'core error', 32 => 'core warning', 64 => 'compile error', 128 => 'compile warning', 256 => 'user error', 512 => 'user warning', 1024 => 'user notice', 2048 => 'strict warning', 4096 => 'recoverable fatal error');
 
     // For database errors, we want the line number/file name of the place that
diff --git a/includes/file.inc b/includes/file.inc
index bbcf9dc6483..6f1bc229ff6 100644
--- a/includes/file.inc
+++ b/includes/file.inc
@@ -403,6 +403,9 @@ function file_munge_filename($filename, $extensions, $alerts = TRUE) {
 
   // Allow potentially insecure uploads for very savvy users and admin
   if (!variable_get('allow_insecure_uploads', 0)) {
+    // Remove any null bytes. See http://php.net/manual/en/security.filesystem.nullbytes.php
+    $filename = str_replace(chr(0), '', $filename);
+
     $whitelist = array_unique(explode(' ', trim($extensions)));
 
     // Split the filename up by periods. The first part becomes the basename
diff --git a/modules/system/system.module b/modules/system/system.module
index 8e9d237519f..08d95bcb4ef 100644
--- a/modules/system/system.module
+++ b/modules/system/system.module
@@ -8,7 +8,7 @@
 /**
  * The current system version.
  */
-define('VERSION', '6.27-dev');
+define('VERSION', '6.27');
 
 /**
  * Core API compatibility.
diff --git a/modules/upload/upload.module b/modules/upload/upload.module
index 3a9e973c3ca..ee5b127ddf5 100644
--- a/modules/upload/upload.module
+++ b/modules/upload/upload.module
@@ -314,10 +314,10 @@ function upload_nodeapi(&$node, $op, $teaser = NULL) {
       break;
 
     case 'search result':
-      return isset($node->files) && is_array($node->files) ? format_plural(count($node->files), '1 attachment', '@count attachments') : NULL;
+      return isset($node->files) && is_array($node->files) && user_access('view uploaded files') ? format_plural(count($node->files), '1 attachment', '@count attachments') : NULL;
 
     case 'rss item':
-      if (is_array($node->files)) {
+      if (is_array($node->files) && user_access('view uploaded files')) {
         $files = array();
         foreach ($node->files as $file) {
           if ($file->list) {
diff --git a/modules/user/user.module b/modules/user/user.module
index 406a6698134..7076226cc86 100644
--- a/modules/user/user.module
+++ b/modules/user/user.module
@@ -599,14 +599,17 @@ function user_search($op = 'search', $keys = NULL, $skip_access_check = FALSE) {
         // Replace wildcards with MySQL/PostgreSQL wildcards.
         $keys = preg_replace('!\*+!', '%', $keys);
         if (user_access('administer users')) {
-          // Administrators can also search in the otherwise private email field.
+          // Administrators can also search in the otherwise private email
+          // field, and they don't need to be restricted to only active users.
           $result = pager_query("SELECT name, uid, mail FROM {users} WHERE LOWER(name) LIKE LOWER('%%%s%%') OR LOWER(mail) LIKE LOWER('%%%s%%')", 15, 0, NULL, $keys, $keys);
           while ($account = db_fetch_object($result)) {
             $find[] = array('title' => $account->name .' ('. $account->mail .')', 'link' => url('user/'. $account->uid, array('absolute' => TRUE)));
           }
         }
         else {
-          $result = pager_query("SELECT name, uid FROM {users} WHERE LOWER(name) LIKE LOWER('%%%s%%')", 15, 0, NULL, $keys);
+          // Regular users can only search via user names, and we do not show
+          // them blocked accounts.
+          $result = pager_query("SELECT name, uid FROM {users} WHERE status = 1 AND LOWER(name) LIKE LOWER('%%%s%%')", 15, 0, NULL, $keys);
           while ($account = db_fetch_object($result)) {
             $find[] = array('title' => $account->name, 'link' => url('user/'. $account->uid, array('absolute' => TRUE)));
           }