diff --git a/VERSIONS_HOTLINE/73509 b/VERSIONS_HOTLINE/73509
new file mode 100644
index 0000000000000000000000000000000000000000..c226d6759cccaad0949cf6d72597d4a6e0de9523
--- /dev/null
+++ b/VERSIONS_HOTLINE/73509
@@ -0,0 +1 @@
+ - ticket #73509 : Explorateur de fichiers : correction de la validation de la taille de fichier, l'explorateur s'appuie désormais sur la configuration courante de PHP (post_max_size et upload_max_filesize)
\ No newline at end of file
diff --git a/library/Class/Php/Config.php b/library/Class/Php/Config.php
new file mode 100644
index 0000000000000000000000000000000000000000..8685008a7fbfe7cad2db1f2cb11d9edda1947c84
--- /dev/null
+++ b/library/Class/Php/Config.php
@@ -0,0 +1,50 @@
+<?php
+/**
+ * Copyright (c) 2012-2017, Agence Française Informatique (AFI). All rights reserved.
+ *
+ * BOKEH is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE as published by
+ * the Free Software Foundation.
+ *
+ * There are special exceptions to the terms and conditions of the AGPL as it
+ * is applied to this software (see README file).
+ *
+ * BOKEH is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
+ *
+ * You should have received a copy of the GNU AFFERO GENERAL PUBLIC LICENSE
+ * along with BOKEH; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
+ */
+
+
+class Class_Php_Config {
+  use Trait_Singleton;
+
+  public function getMaxFileSize() {
+    $ini_post_max_size = ini_get('post_max_size');
+    $post_max_size = $this->_sizeToBytes($ini_post_max_size);
+
+    $ini_upload_max_filesize = ini_get('upload_max_filesize');
+    $upload_max = $this->_sizeToBytes($ini_upload_max_filesize);
+
+    if (!$upload_max && !$post_max_size)
+      return;
+
+    return $upload_max < $post_max_size
+      ? $ini_upload_max_filesize
+      : $ini_post_max_size;
+  }
+
+
+  protected function _sizeToBytes($size) {
+    $unit = preg_replace('/[^bkmgtpezy]/i', '', $size);
+    $size = preg_replace('/[^0-9\.]/', '', $size);
+
+    return $unit
+      ? round($size * pow(1024, stripos('bkmgtpezy', $unit[0])))
+      : round($size);
+  }
+}
diff --git a/library/ZendAfi/Form/Admin/FileManager/Import.php b/library/ZendAfi/Form/Admin/FileManager/Import.php
index b3ecc5c5c6bdd8fc9c4d2e1091aaa7eeb58d6755..9a46e554925f20cf939c070f96bbe063a965a38a 100644
--- a/library/ZendAfi/Form/Admin/FileManager/Import.php
+++ b/library/ZendAfi/Form/Admin/FileManager/Import.php
@@ -41,22 +41,33 @@ class ZendAfi_Form_Admin_FileManager_Import extends ZendAfi_Form {
       return $element;
 
     $extensions = Class_AdminVar::get('ALLOWED_FILES_EXTENSIONS_FOR_IMPORT');
+    $not_found_message = [$form->_('Un problème est survenu lors du transfert.')];
+    $php_config = Class_Php_Config::getInstance();
+    if ($max_file_size = $php_config->getMaxFileSize())
+      $not_found_message[] = $form->_('Veuillez vérifier que la taille du fichier ne dépasse pas le maximum autorisé de %s',
+                                      $max_file_size);
+
+    $file_extension_validator = (new ZendAfi_Validate_FileExtension(explode(';', $extensions)))
+      ->setMessage($form->_('Les extensions possibles sont : %s', $extensions),
+                   ZendAfi_Validate_FileExtension::FALSE_EXTENSION)
+
+      ->setMessage(implode(' ', $not_found_message),
+                   ZendAfi_Validate_FileExtension::NOT_FOUND);
+
+    $element
+      ->addValidator($file_extension_validator, true)
 
-    return $element
       ->addValidator((new ZendAfi_Validate_FileName(Class_FileManager::REGEX_NAME))
                      ->setMessage($form->_('Le nom doit contenir uniquement des lettres, des chiffres et les caratères "_", "-", ".". Exemple : "mon_fichier.jpg"'),
                                   ZendAfi_Validate_FileName::NOT_MATCH))
 
       ->addValidator((new Zend_Validate_File_Count(1))
-                     ->setMessage($form->_('Un seul fichier doit être transféré.')))
+                     ->setMessage($form->_('Un seul fichier doit être transféré.')));
+
+
 
-      ->addValidator((new Zend_Validate_File_Size('1', '10000000', true))
-                     ->setMessage($form->_('La taille du fichier doit être supérieur à "%min%"'), Zend_Validate_File_Size::TOO_SMALL)
-                     ->setMessage($form->_('La taille du fichier doit être inférieur à "%max%"'), Zend_Validate_File_Size::TOO_BIG)
-                     ->setMessage($form->_('Le fichier n\'est pas lisible'), Zend_Validate_File_Size::NOT_FOUND))
 
-      ->addValidator((new Zend_Validate_File_Extension(explode(';', $extensions)))
-                     ->setMessage($form->_('Les extensions possibles sont : %s', $extensions)));
+    return $element;
   }
 
 
diff --git a/library/ZendAfi/Validate/FileExtension.php b/library/ZendAfi/Validate/FileExtension.php
new file mode 100644
index 0000000000000000000000000000000000000000..1f374bcc0bc0c8d6fccab84b6e84de4f8066c66b
--- /dev/null
+++ b/library/ZendAfi/Validate/FileExtension.php
@@ -0,0 +1,68 @@
+<?php
+/**
+ * Copyright (c) 2012-2017, Agence Française Informatique (AFI). All rights reserved.
+ *
+ * BOKEH is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE as published by
+ * the Free Software Foundation.
+ *
+ * There are special exceptions to the terms and conditions of the AGPL as it
+ * is applied to this software (see README file).
+ *
+ * BOKEH is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
+ *
+ * You should have received a copy of the GNU AFFERO GENERAL PUBLIC LICENSE
+ * along with BOKEH; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
+ */
+
+
+class ZendAfi_Validate_FileExtension extends Zend_Validate_File_Extension {
+  use Trait_StaticFileSystem;
+
+  /**
+   * Testable version of parent method
+   *
+   * Returns true if and only if the fileextension of $value is included in the
+   * set extension list
+   *
+   * @param  string  $value Real file to check for extension
+   * @param  array   $file  File data from Zend_File_Transfer
+   * @return boolean
+   */
+  public function isValid($value, $file = null)
+  {
+    $filesystem = static::getFileSystem();
+
+    // Is file readable ?
+    if (!@$filesystem->is_readable($value)) {
+      $this->_throw($file, self::NOT_FOUND);
+      return false;
+    }
+
+    if ($file !== null) {
+      $info['extension'] = substr($file['name'], strrpos($file['name'], '.') + 1);
+    } else {
+      $info = @$filesystem->pathinfo($value);
+    }
+
+    $extensions = $this->getExtension(true);
+
+    if ($this->_case and (in_array($info['extension'], $extensions)))
+      return true;
+
+    if (!$this->_case) {
+      foreach ($extensions as $extension) {
+        if (strtolower($extension) == strtolower($info['extension'])) {
+          return true;
+        }
+      }
+    }
+
+    $this->_throw($file, self::FALSE_EXTENSION);
+    return false;
+  }
+}
diff --git a/tests/application/modules/admin/controllers/FileManagerControllerTest.php b/tests/application/modules/admin/controllers/FileManagerControllerTest.php
index b82ea59064f7ee823b7145273d34ef046ef2efe7..26ef5578a5f71c24e99e9132b46306ff615088f9 100644
--- a/tests/application/modules/admin/controllers/FileManagerControllerTest.php
+++ b/tests/application/modules/admin/controllers/FileManagerControllerTest.php
@@ -105,6 +105,10 @@ abstract class FileManagerControllerTestCase extends Admin_AbstractControllerTes
                    ['id' => 'RESIZABLE_EXTENSIONS',
                     'valeur' => 'jpg;jpeg;png']);
 
+    $this->fixture('Class_AdminVar',
+                   ['id' => 'ALLOWED_FILES_EXTENSIONS_FOR_IMPORT',
+                    'valeur' => 'css;jpg;jpeg;png']);
+
     $this->_userfiles_dir = (new Class_FileManager)
       ->setId('userfiles')
       ->setDir(true)
@@ -712,8 +716,15 @@ class FileManagerControllerImportCssDispatchTest extends FileManagerControllerTe
                          'size'     => 126976,
                          'tmp_name' => 'xxxxx/php8iuxxajl']];
 
-    ZendAfi_Form_Admin_FileManager_Import::setTransferAdapter((new FileManagerController_Mock_TransferAdapter())->setFiles($files));
-    ZendAfi_Form_Admin_FileManager_Import::setValidators(null);
+    $adapter = (new FileManagerController_Mock_TransferAdapter())->setFiles($files);
+    ZendAfi_Form_Admin_FileManager_Import::setTransferAdapter($adapter);
+
+    $filesystem = $this
+      ->mock()
+      ->whenCalled('is_readable')->with('xxxxx/php8iuxxajl')->answers(true)
+      ->whenCalled('filesize')->with('xxxxx/php8iuxxajl')->answers(126976);
+
+    ZendAfi_Validate_FileExtension::setFileSystem($filesystem);
 
     $imported_file = (new Class_FileManager)
       ->setId('userfiles/stylesheet.css')
@@ -738,6 +749,14 @@ class FileManagerControllerImportCssDispatchTest extends FileManagerControllerTe
   }
 
 
+  public function tearDown() {
+    ZendAfi_Validate_FileExtension::setFileSystem(null);
+    Class_Php_Config::setInstance(null);
+
+    parent::tearDown();
+  }
+
+
   /** @test */
   public function dispatchFormShouldContainsInputFile() {
     $this->dispatch('/admin/file-manager/import?into=userfiles', true);
@@ -754,7 +773,8 @@ class FileManagerControllerImportCssDispatchTest extends FileManagerControllerTe
 
   /** @test */
   public function postDispatchImportShouldRedirectWithSucces() {
-    $this->postDispatch('/admin/file-manager/import?into=userfiles', ['file' => 'stylesheet.css']);
+    $this->postDispatch('/admin/file-manager/import?into=userfiles',
+                        ['file' => 'stylesheet.css']);
     $this->assertFlashMessengerContentContains('Fichier "userfiles/stylesheet.css" téléversé.');
     $this->assertRedirectTo('/admin/file-manager/index?browser=userfiles%2Fstylesheet.css');
   }
@@ -767,6 +787,20 @@ class FileManagerControllerImportCssDispatchTest extends FileManagerControllerTe
     $this->assertFlashMessengerContentContains('Fichier "userfiles/stylesheet.css" téléversé.');
     $this->assertRedirectTo('/admin/file-manager/index?browser=userfiles%2Fstylesheet.css&selectable_extensions=css');
   }
+
+
+  /** @test */
+  public function postDispatchImportFileSizeTooBigShouldDisplayErrorWithMaxFileSize() {
+    ZendAfi_Validate_FileExtension::setFileSystem($this->mock()
+                                                  ->whenCalled('is_readable')
+                                                  ->answers(false));
+
+    Class_Php_Config::setInstance($this->mock()
+                                  ->whenCalled('getMaxFileSize')->answers('10M'));
+    $this->postDispatch('/admin/file-manager/import?into=userfiles&selectable_extensions=css',
+                        ['file' => 'stylesheet.css']);
+    $this->assertXPathContentContains('//ul[@class="errors"]/li', '10M');
+  }
 }