diff --git a/src/Symfony/Component/HttpFoundation/Request.php b/src/Symfony/Component/HttpFoundation/Request.php
index af00561a01..9f12d51999 100644
--- a/src/Symfony/Component/HttpFoundation/Request.php
+++ b/src/Symfony/Component/HttpFoundation/Request.php
@@ -292,7 +292,7 @@ class Request
     {
         $request = self::createRequestFromFactory($_GET, $_POST, [], $_COOKIE, $_FILES, $_SERVER);
 
-        if (0 === strpos($request->headers->get('CONTENT_TYPE'), 'application/x-www-form-urlencoded')
+        if (0 === strpos($request->headers->get('CONTENT_TYPE', ''), 'application/x-www-form-urlencoded')
             && \in_array(strtoupper($request->server->get('REQUEST_METHOD', 'GET')), ['PUT', 'DELETE', 'PATCH'])
         ) {
             parse_str($request->getContent(), $data);
@@ -1391,7 +1391,7 @@ class Request
      */
     public function getContentType()
     {
-        return $this->getFormat($this->headers->get('CONTENT_TYPE'));
+        return $this->getFormat($this->headers->get('CONTENT_TYPE', ''));
     }
 
     /**
@@ -1564,7 +1564,7 @@ class Request
      */
     public function getETags()
     {
-        return preg_split('/\s*,\s*/', $this->headers->get('if_none_match'), -1, \PREG_SPLIT_NO_EMPTY);
+        return preg_split('/\s*,\s*/', $this->headers->get('if_none_match', ''), -1, \PREG_SPLIT_NO_EMPTY);
     }
 
     /**
@@ -1790,13 +1790,13 @@ class Request
      */
     protected function prepareBaseUrl()
     {
-        $filename = basename($this->server->get('SCRIPT_FILENAME'));
+        $filename = basename($this->server->get('SCRIPT_FILENAME', ''));
 
-        if (basename($this->server->get('SCRIPT_NAME')) === $filename) {
+        if (basename($this->server->get('SCRIPT_NAME', '')) === $filename) {
             $baseUrl = $this->server->get('SCRIPT_NAME');
-        } elseif (basename($this->server->get('PHP_SELF')) === $filename) {
+        } elseif (basename($this->server->get('PHP_SELF', '')) === $filename) {
             $baseUrl = $this->server->get('PHP_SELF');
-        } elseif (basename($this->server->get('ORIG_SCRIPT_NAME')) === $filename) {
+        } elseif (basename($this->server->get('ORIG_SCRIPT_NAME', '')) === $filename) {
             $baseUrl = $this->server->get('ORIG_SCRIPT_NAME'); // 1and1 shared hosting compatibility
         } else {
             // Backtrack up the script_filename to find the portion matching
@@ -1836,7 +1836,7 @@ class Request
             $truncatedRequestUri = substr($requestUri, 0, $pos);
         }
 
-        $basename = basename($baseUrl);
+        $basename = basename($baseUrl ?? '');
         if (empty($basename) || !strpos(rawurldecode($truncatedRequestUri), $basename)) {
             // no match whatsoever; set it blank
             return '';
@@ -1987,7 +1987,7 @@ class Request
      */
     public function isFromTrustedProxy()
     {
-        return self::$trustedProxies && IpUtils::checkIp($this->server->get('REMOTE_ADDR'), self::$trustedProxies);
+        return self::$trustedProxies && IpUtils::checkIp($this->server->get('REMOTE_ADDR', ''), self::$trustedProxies);
     }
 
     private function getTrustedValues(int $type, string $ip = null): array
diff --git a/src/Symfony/Component/HttpFoundation/Tests/Fixtures/response-functional/cookie_raw_urlencode.php b/src/Symfony/Component/HttpFoundation/Tests/Fixtures/response-functional/cookie_raw_urlencode.php
index 00c022d953..4b96ddab36 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/Fixtures/response-functional/cookie_raw_urlencode.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/Fixtures/response-functional/cookie_raw_urlencode.php
@@ -9,4 +9,4 @@ $str = '?*():@&+$/%#[]';
 $r->headers->setCookie(new Cookie($str, $str, 0, '/', null, false, false, true, null));
 $r->sendHeaders();
 
-setrawcookie($str, $str, 0, '/', null, false, false);
+setrawcookie($str, $str, 0, '/', '', false, false);
diff --git a/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php b/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
index c777283b66..798c355d37 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
@@ -446,7 +446,7 @@ class RequestTest extends TestCase
     public function getFormatToMimeTypeMapProviderWithAdditionalNullFormat()
     {
         return array_merge(
-            [[null, [null, 'unexistent-mime-type']]],
+            [[null, ['unexistent-mime-type']]],
             $this->getFormatToMimeTypeMapProvider()
         );
     }