diff --git a/DataCollector/RequestDataCollector.php b/DataCollector/RequestDataCollector.php
index 523f5c957f..951860a225 100644
--- a/DataCollector/RequestDataCollector.php
+++ b/DataCollector/RequestDataCollector.php
@@ -110,7 +110,7 @@ public function collect(Request $request, Response $response, \Throwable $except
             'session_metadata' => $sessionMetadata,
             'session_attributes' => $sessionAttributes,
             'session_usages' => array_values($this->sessionUsages),
-            'stateless_check' => $this->requestStack && $this->requestStack->getMainRequest()->attributes->get('_stateless', false),
+            'stateless_check' => $this->requestStack && ($mainRequest = $this->requestStack->getMainRequest()) && $mainRequest->attributes->get('_stateless', false),
             'flashes' => $flashes,
             'path_info' => $request->getPathInfo(),
             'controller' => 'n/a',
diff --git a/Kernel.php b/Kernel.php
index efedd884ad..93068eda13 100644
--- a/Kernel.php
+++ b/Kernel.php
@@ -78,11 +78,11 @@ abstract class Kernel implements KernelInterface, RebootableInterface, Terminabl
      */
     private static $freshCache = [];
 
-    public const VERSION = '5.4.12';
-    public const VERSION_ID = 50412;
+    public const VERSION = '5.4.13';
+    public const VERSION_ID = 50413;
     public const MAJOR_VERSION = 5;
     public const MINOR_VERSION = 4;
-    public const RELEASE_VERSION = 12;
+    public const RELEASE_VERSION = 13;
     public const EXTRA_VERSION = '';
 
     public const END_OF_MAINTENANCE = '11/2024';
diff --git a/Profiler/FileProfilerStorage.php b/Profiler/FileProfilerStorage.php
index 3e7b1bd884..0b5a780abd 100644
--- a/Profiler/FileProfilerStorage.php
+++ b/Profiler/FileProfilerStorage.php
@@ -115,19 +115,7 @@ public function purge()
      */
     public function read(string $token): ?Profile
     {
-        if (!$token || !file_exists($file = $this->getFilename($token))) {
-            return null;
-        }
-
-        if (\function_exists('gzcompress')) {
-            $file = 'compress.zlib://'.$file;
-        }
-
-        if (!$data = unserialize(file_get_contents($file))) {
-            return null;
-        }
-
-        return $this->createProfileFromData($token, $data);
+        return $this->doRead($token);
     }
 
     /**
@@ -169,14 +157,13 @@ public function write(Profile $profile): bool
             'status_code' => $profile->getStatusCode(),
         ];
 
-        $context = stream_context_create();
+        $data = serialize($data);
 
-        if (\function_exists('gzcompress')) {
-            $file = 'compress.zlib://'.$file;
-            stream_context_set_option($context, 'zlib', 'level', 3);
+        if (\function_exists('gzencode')) {
+            $data = gzencode($data, 3);
         }
 
-        if (false === file_put_contents($file, serialize($data), 0, $context)) {
+        if (false === file_put_contents($file, $data, \LOCK_EX)) {
             return false;
         }
 
@@ -291,21 +278,34 @@ protected function createProfileFromData(string $token, array $data, Profile $pa
         }
 
         foreach ($data['children'] as $token) {
-            if (!$token || !file_exists($file = $this->getFilename($token))) {
-                continue;
+            if (null !== $childProfile = $this->doRead($token, $profile)) {
+                $profile->addChild($childProfile);
             }
+        }
 
-            if (\function_exists('gzcompress')) {
-                $file = 'compress.zlib://'.$file;
-            }
+        return $profile;
+    }
 
-            if (!$childData = unserialize(file_get_contents($file))) {
-                continue;
-            }
+    private function doRead($token, Profile $profile = null): ?Profile
+    {
+        if (!$token || !file_exists($file = $this->getFilename($token))) {
+            return null;
+        }
+
+        $h = fopen($file, 'r');
+        flock($h, \LOCK_SH);
+        $data = stream_get_contents($h);
+        flock($h, \LOCK_UN);
+        fclose($h);
 
-            $profile->addChild($this->createProfileFromData($token, $childData, $profile));
+        if (\function_exists('gzdecode')) {
+            $data = @gzdecode($data) ?: $data;
         }
 
-        return $profile;
+        if (!$data = unserialize($data)) {
+            return null;
+        }
+
+        return $this->createProfileFromData($token, $data, $profile);
     }
 }
diff --git a/Tests/DataCollector/RequestDataCollectorTest.php b/Tests/DataCollector/RequestDataCollectorTest.php
index 0c576e00ed..d7c8b302b6 100644
--- a/Tests/DataCollector/RequestDataCollectorTest.php
+++ b/Tests/DataCollector/RequestDataCollectorTest.php
@@ -312,6 +312,15 @@ public function testStatelessCheck()
         $collector->lateCollect();
 
         $this->assertTrue($collector->getStatelessCheck());
+
+        $requestStack = new RequestStack();
+        $request = $this->createRequest();
+
+        $collector = new RequestDataCollector($requestStack);
+        $collector->collect($request, $response = $this->createResponse());
+        $collector->lateCollect();
+
+        $this->assertFalse($collector->getStatelessCheck());
     }
 
     public function testItHidesPassword()
diff --git a/Tests/EventListener/LocaleListenerTest.php b/Tests/EventListener/LocaleListenerTest.php
index 4c1c624de2..824d906340 100644
--- a/Tests/EventListener/LocaleListenerTest.php
+++ b/Tests/EventListener/LocaleListenerTest.php
@@ -120,7 +120,7 @@ public function testRequestLocaleIsNotOverridden()
     public function testRequestPreferredLocaleFromAcceptLanguageHeader()
     {
         $request = Request::create('/');
-        $request->headers->set('Accept-Language', ['Accept-Language: fr-FR,fr;q=0.9,en-GB;q=0.8,en;q=0.7,en-US;q=0.6,es;q=0.5']);
+        $request->headers->set('Accept-Language', 'fr-FR,fr;q=0.9,en-GB;q=0.8,en;q=0.7,en-US;q=0.6,es;q=0.5');
 
         $listener = new LocaleListener($this->requestStack, 'de', null, true, ['de', 'fr']);
         $event = $this->getEvent($request);
@@ -133,7 +133,7 @@ public function testRequestPreferredLocaleFromAcceptLanguageHeader()
     public function testRequestSecondPreferredLocaleFromAcceptLanguageHeader()
     {
         $request = Request::create('/');
-        $request->headers->set('Accept-Language', ['Accept-Language: fr-FR,fr;q=0.9,en-GB;q=0.8,en;q=0.7,en-US;q=0.6,es;q=0.5']);
+        $request->headers->set('Accept-Language', 'fr-FR,fr;q=0.9,en-GB;q=0.8,en;q=0.7,en-US;q=0.6,es;q=0.5');
 
         $listener = new LocaleListener($this->requestStack, 'de', null, true, ['de', 'en']);
         $event = $this->getEvent($request);
@@ -146,7 +146,7 @@ public function testRequestSecondPreferredLocaleFromAcceptLanguageHeader()
     public function testDontUseAcceptLanguageHeaderIfNotEnabled()
     {
         $request = Request::create('/');
-        $request->headers->set('Accept-Language', ['Accept-Language: fr-FR,fr;q=0.9,en-GB;q=0.8,en;q=0.7,en-US;q=0.6,es;q=0.5']);
+        $request->headers->set('Accept-Language', 'fr-FR,fr;q=0.9,en-GB;q=0.8,en;q=0.7,en-US;q=0.6,es;q=0.5');
 
         $listener = new LocaleListener($this->requestStack, 'de', null, false, ['de', 'en']);
         $event = $this->getEvent($request);
@@ -159,7 +159,7 @@ public function testDontUseAcceptLanguageHeaderIfNotEnabled()
     public function testRequestUnavailablePreferredLocaleFromAcceptLanguageHeader()
     {
         $request = Request::create('/');
-        $request->headers->set('Accept-Language', ['Accept-Language: fr-FR,fr;q=0.9,en-GB;q=0.8,en;q=0.7,en-US;q=0.6,es;q=0.5']);
+        $request->headers->set('Accept-Language', 'fr-FR,fr;q=0.9,en-GB;q=0.8,en;q=0.7,en-US;q=0.6,es;q=0.5');
 
         $listener = new LocaleListener($this->requestStack, 'de', null, true, ['de', 'it']);
         $event = $this->getEvent($request);
@@ -172,7 +172,7 @@ public function testRequestUnavailablePreferredLocaleFromAcceptLanguageHeader()
     public function testRequestNoLocaleFromAcceptLanguageHeader()
     {
         $request = Request::create('/');
-        $request->headers->set('Accept-Language', ['Accept-Language: fr-FR,fr;q=0.9,en-GB;q=0.8,en;q=0.7,en-US;q=0.6,es;q=0.5']);
+        $request->headers->set('Accept-Language', 'fr-FR,fr;q=0.9,en-GB;q=0.8,en;q=0.7,en-US;q=0.6,es;q=0.5');
 
         $listener = new LocaleListener($this->requestStack, 'de', null, true);
         $event = $this->getEvent($request);
@@ -186,7 +186,7 @@ public function testRequestAttributeLocaleNotOverridenFromAcceptLanguageHeader()
     {
         $request = Request::create('/');
         $request->attributes->set('_locale', 'it');
-        $request->headers->set('Accept-Language', ['Accept-Language: fr-FR,fr;q=0.9,en-GB;q=0.8,en;q=0.7,en-US;q=0.6,es;q=0.5']);
+        $request->headers->set('Accept-Language', 'fr-FR,fr;q=0.9,en-GB;q=0.8,en;q=0.7,en-US;q=0.6,es;q=0.5');
 
         $listener = new LocaleListener($this->requestStack, 'de', null, true, ['fr', 'en']);
         $event = $this->getEvent($request);