diff --git a/composer.json b/composer.json
index 1cba7fe..06ce556 100644
--- a/composer.json
+++ b/composer.json
@@ -36,6 +36,7 @@
         "ext-json": "*",
         "ext-simplexml": "*",
         "ext-mbstring": "*",
+        "ext-libxml": "*",
         "guzzlehttp/guzzle": "^6.2.1 || ^7.0",
         "guzzlehttp/guzzle-services": "^1.1",
         "guzzlehttp/psr7": "^1.3.1 || ^2.0"
diff --git a/src/Client.php b/src/Client.php
index d9614ae..c739b9f 100644
--- a/src/Client.php
+++ b/src/Client.php
@@ -553,10 +553,29 @@ public function upload($bucket, $key, $body, $options = array()) {
         return $rt;
     }
 
+    public static function simplifyPath($path) {
+        $names = explode("/", $path);
+        $stack = array();
+        foreach ($names as $name) {
+            if ($name == "..") {
+                if (!empty($stack)) {
+                    array_pop($stack);
+                }
+            } elseif ($name && $name != ".") {
+                array_push($stack, $name);
+            }
+        }
+        return "/" . implode("/", $stack);
+    }
+
     public function download($bucket, $key, $saveAs, $options = array()) {
         $options['PartSize'] = isset($options['PartSize']) ? $options['PartSize'] : RangeDownload::DEFAULT_PART_SIZE;
         $versionId = isset($options['VersionId']) ? $options['VersionId'] : '';
-
+        if ("/" == self::simplifyPath($key)) {
+            $e = new Exception\CosException('GET OBEJCT NOT FOUND');
+            $e->setExceptionCode('404');
+            throw $e;
+        }
         $rt = $this->headObject(array(
                 'Bucket'=>$bucket,
                 'Key'=>$key,
@@ -664,6 +683,12 @@ public function doesObjectExist($bucket, $key, array $options = array())
     }
     
     public static function explodeKey($key) {
+
+        if ("/" == self::simplifyPath($key)) {
+            $e = new Exception\CosException('GET OBEJCT NOT FOUND');
+            $e->setExceptionCode('404');
+            throw $e;
+        }
         // Remove a leading slash if one is found
         $split_key = explode('/', $key && $key[0] == '/' ? substr($key, 1) : $key);
         // Remove empty element
diff --git a/src/ResultTransformer.php b/src/ResultTransformer.php
index 9c97aa5..c3ca718 100644
--- a/src/ResultTransformer.php
+++ b/src/ResultTransformer.php
@@ -86,6 +86,9 @@ public function ciContentInfoTransformer(CommandInterface $command, Result $resu
             $length = intval($result['ContentLength']);
             if($length > 0){
                 $content = $this->geCiContentInfo($result, $length);
+                if (version_compare(PHP_VERSION, '8.0.0', '<')) {
+                    libxml_disable_entity_loader(true);
+                }
                 $obj = simplexml_load_string($content, "SimpleXMLElement", LIBXML_NOCDATA);
                 $xmlData = json_decode(json_encode($obj),true);
                 if ($picRuleSize == 1 && isset($xmlData['ProcessResults']['Object'])){
@@ -101,6 +104,9 @@ public function ciContentInfoTransformer(CommandInterface $command, Result $resu
             $length = intval($result['ContentLength']);
             if($length > 0){
                 $content = $this->geCiContentInfo($result, $length);
+                if (version_compare(PHP_VERSION, '8.0.0', '<')) {
+                    libxml_disable_entity_loader(true);
+                }
                 $obj = simplexml_load_string($content, "SimpleXMLElement", LIBXML_NOCDATA);
                 $arr = json_decode(json_encode($obj),true);
                 $result['GuetzliStatus'] = isset($arr[0]) ? $arr[0] : '';
@@ -111,6 +117,9 @@ public function ciContentInfoTransformer(CommandInterface $command, Result $resu
             $length = intval($result['ContentLength']);
             if($length > 0){
                 $content = $this->geCiContentInfo($result, $length);
+                if (version_compare(PHP_VERSION, '8.0.0', '<')) {
+                    libxml_disable_entity_loader(true);
+                }
                 $obj = simplexml_load_string($content, "SimpleXMLElement", LIBXML_NOCDATA);
                 $arr = json_decode(json_encode($obj),true);
                 $result['CIStatus'] = isset($arr[0]) ? $arr[0] : '';
@@ -122,6 +131,9 @@ public function ciContentInfoTransformer(CommandInterface $command, Result $resu
             $length = intval($result['ContentLength']);
             if($length > 0){
                 $content = $this->geCiContentInfo($result, $length);
+                if (version_compare(PHP_VERSION, '8.0.0', '<')) {
+                    libxml_disable_entity_loader(true);
+                }
                 $obj = simplexml_load_string($content, "SimpleXMLElement", LIBXML_NOCDATA);
                 $arr = json_decode(json_encode($obj),true);
                 $result['OriginProtectStatus'] = isset($arr[0]) ? $arr[0] : '';
@@ -133,6 +145,9 @@ public function ciContentInfoTransformer(CommandInterface $command, Result $resu
             $length = intval($result['ContentLength']);
             if($length > 0){
                 $content = $this->geCiContentInfo($result, $length);
+                if (version_compare(PHP_VERSION, '8.0.0', '<')) {
+                    libxml_disable_entity_loader(true);
+                }
                 $obj = simplexml_load_string($content, "SimpleXMLElement", LIBXML_NOCDATA);
                 $arr = json_decode(json_encode($obj),true);
                 $result['Hotlink'] = $arr;
@@ -144,6 +159,9 @@ public function ciContentInfoTransformer(CommandInterface $command, Result $resu
             $length = intval($result['ContentLength']);
             if($length > 0){
                 $content = $this->geCiContentInfo($result, $length);
+                if (version_compare(PHP_VERSION, '8.0.0', '<')) {
+                    libxml_disable_entity_loader(true);
+                }
                 $obj = simplexml_load_string($content, "SimpleXMLElement", LIBXML_NOCDATA);
                 $arr = json_decode(json_encode($obj),true);
                 $result['TranslationResult'] = isset($arr[0]) ? $arr[0] : '';
@@ -204,6 +222,9 @@ public function ciContentInfoTransformer(CommandInterface $command, Result $resu
             $length = intval($result['ContentLength']);
             if($length > 0){
                 $content = $this->geCiContentInfo($result, $length);
+                if (version_compare(PHP_VERSION, '8.0.0', '<')) {
+                    libxml_disable_entity_loader(true);
+                }
                 $obj = simplexml_load_string($content, "SimpleXMLElement", LIBXML_NOCDATA);
                 $xmlData = json_decode(json_encode($obj),true);
                 $result['Response'] = $xmlData;