diff --git a/lib/htmlpurifier/HTMLPurifier.php b/lib/htmlpurifier/HTMLPurifier.php
index 6f0fa811a74..a8ccb0d8941 100644
--- a/lib/htmlpurifier/HTMLPurifier.php
+++ b/lib/htmlpurifier/HTMLPurifier.php
@@ -19,7 +19,7 @@
  */
 
 /*
-    HTML Purifier 4.10.0 - Standards Compliant HTML Filtering
+    HTML Purifier 4.12.0 - Standards Compliant HTML Filtering
     Copyright (C) 2006-2008 Edward Z. Yang
 
     This library is free software; you can redistribute it and/or
@@ -58,12 +58,12 @@ class HTMLPurifier
      * Version of HTML Purifier.
      * @type string
      */
-    public $version = '4.10.0';
+    public $version = '4.12.0';
 
     /**
      * Constant with version of HTML Purifier.
      */
-    const VERSION = '4.10.0';
+    const VERSION = '4.12.0';
 
     /**
      * Global configuration object.
@@ -240,12 +240,16 @@ class HTMLPurifier
     public function purifyArray($array_of_html, $config = null)
     {
         $context_array = array();
-        foreach ($array_of_html as $key => $html) {
-            $array_of_html[$key] = $this->purify($html, $config);
+        foreach($array_of_html as $key=>$value){
+            if (is_array($value)) {
+                $array[$key] = $this->purifyArray($value, $config);
+            } else {
+                $array[$key] = $this->purify($value, $config);
+            }
             $context_array[$key] = $this->context;
         }
         $this->context = $context_array;
-        return $array_of_html;
+        return $array;
     }
 
     /**
diff --git a/lib/htmlpurifier/HTMLPurifier/AttrDef/HTML/Bool.php b/lib/htmlpurifier/HTMLPurifier/AttrDef/HTML/Bool.php
index 953a36a6c90..bf54e8ef4ce 100644
--- a/lib/htmlpurifier/HTMLPurifier/AttrDef/HTML/Bool.php
+++ b/lib/htmlpurifier/HTMLPurifier/AttrDef/HTML/Bool.php
@@ -7,7 +7,7 @@ class HTMLPurifier_AttrDef_HTML_Bool extends HTMLPurifier_AttrDef
 {
 
     /**
-     * @type bool
+     * @type string
      */
     protected $name;
 
@@ -17,7 +17,7 @@ class HTMLPurifier_AttrDef_HTML_Bool extends HTMLPurifier_AttrDef
     public $minimized = true;
 
     /**
-     * @param bool $name
+     * @param bool|string $name
      */
     public function __construct($name = false)
     {
diff --git a/lib/htmlpurifier/HTMLPurifier/AttrDef/URI/Host.php b/lib/htmlpurifier/HTMLPurifier/AttrDef/URI/Host.php
index c1e2e3c5ddd..a61111e0cfe 100644
--- a/lib/htmlpurifier/HTMLPurifier/AttrDef/URI/Host.php
+++ b/lib/htmlpurifier/HTMLPurifier/AttrDef/URI/Host.php
@@ -97,7 +97,11 @@ class HTMLPurifier_AttrDef_URI_Host extends HTMLPurifier_AttrDef
 
         // PHP 5.3 and later support this functionality natively
         if (function_exists('idn_to_ascii')) {
-            $string = idn_to_ascii($string, IDNA_NONTRANSITIONAL_TO_ASCII, INTL_IDNA_VARIANT_UTS46);
+            if (defined('IDNA_NONTRANSITIONAL_TO_ASCII') && defined('INTL_IDNA_VARIANT_UTS46')) {
+                $string = idn_to_ascii($string, IDNA_NONTRANSITIONAL_TO_ASCII, INTL_IDNA_VARIANT_UTS46);
+            } else {
+                $string = idn_to_ascii($string);
+            }
 
         // If we have Net_IDNA2 support, we can support IRIs by
         // punycoding them. (This is the most portable thing to do,
diff --git a/lib/htmlpurifier/HTMLPurifier/CSSDefinition.php b/lib/htmlpurifier/HTMLPurifier/CSSDefinition.php
index 5e7490eb2d6..ca3dcd662a1 100644
--- a/lib/htmlpurifier/HTMLPurifier/CSSDefinition.php
+++ b/lib/htmlpurifier/HTMLPurifier/CSSDefinition.php
@@ -220,15 +220,25 @@ class HTMLPurifier_CSSDefinition extends HTMLPurifier_Definition
             array(
                 new HTMLPurifier_AttrDef_CSS_Length('0'),
                 new HTMLPurifier_AttrDef_CSS_Percentage(true),
-                new HTMLPurifier_AttrDef_Enum(array('auto'))
+                new HTMLPurifier_AttrDef_Enum(array('auto', 'initial', 'inherit'))
+            )
+        );
+        $trusted_min_wh = new HTMLPurifier_AttrDef_CSS_Composite(
+            array(
+                new HTMLPurifier_AttrDef_CSS_Length('0'),
+                new HTMLPurifier_AttrDef_CSS_Percentage(true),
+                new HTMLPurifier_AttrDef_Enum(array('initial', 'inherit'))
+            )
+        );
+        $trusted_max_wh = new HTMLPurifier_AttrDef_CSS_Composite(
+            array(
+                new HTMLPurifier_AttrDef_CSS_Length('0'),
+                new HTMLPurifier_AttrDef_CSS_Percentage(true),
+                new HTMLPurifier_AttrDef_Enum(array('none', 'initial', 'inherit'))
             )
         );
         $max = $config->get('CSS.MaxImgLength');
 
-        $this->info['min-width'] =
-        $this->info['max-width'] =
-        $this->info['min-height'] =
-        $this->info['max-height'] =
         $this->info['width'] =
         $this->info['height'] =
             $max === null ?
@@ -245,6 +255,38 @@ class HTMLPurifier_CSSDefinition extends HTMLPurifier_Definition
                     // For everyone else:
                     $trusted_wh
                 );
+        $this->info['min-width'] =
+        $this->info['min-height'] =
+            $max === null ?
+                $trusted_min_wh :
+                new HTMLPurifier_AttrDef_Switch(
+                    'img',
+                    // For img tags:
+                    new HTMLPurifier_AttrDef_CSS_Composite(
+                        array(
+                            new HTMLPurifier_AttrDef_CSS_Length('0', $max),
+                            new HTMLPurifier_AttrDef_Enum(array('initial', 'inherit'))
+                        )
+                    ),
+                    // For everyone else:
+                    $trusted_min_wh
+                );
+        $this->info['max-width'] =
+        $this->info['max-height'] =
+            $max === null ?
+                $trusted_max_wh :
+                new HTMLPurifier_AttrDef_Switch(
+                    'img',
+                    // For img tags:
+                    new HTMLPurifier_AttrDef_CSS_Composite(
+                        array(
+                            new HTMLPurifier_AttrDef_CSS_Length('0', $max),
+                            new HTMLPurifier_AttrDef_Enum(array('none', 'initial', 'inherit'))
+                        )
+                    ),
+                    // For everyone else:
+                    $trusted_max_wh
+                );
 
         $this->info['text-decoration'] = new HTMLPurifier_AttrDef_CSS_TextDecoration();
 
diff --git a/lib/htmlpurifier/HTMLPurifier/Config.php b/lib/htmlpurifier/HTMLPurifier/Config.php
index 0d89bc208cd..0a7e09f6046 100644
--- a/lib/htmlpurifier/HTMLPurifier/Config.php
+++ b/lib/htmlpurifier/HTMLPurifier/Config.php
@@ -21,7 +21,7 @@ class HTMLPurifier_Config
      * HTML Purifier's version
      * @type string
      */
-    public $version = '4.10.0';
+    public $version = '4.12.0';
 
     /**
      * Whether or not to automatically finalize
@@ -890,7 +890,7 @@ class HTMLPurifier_Config
             // zip(tail(trace), trace) -- but PHP is not Haskell har har
             for ($i = 0, $c = count($trace); $i < $c - 1; $i++) {
                 // XXX this is not correct on some versions of HTML Purifier
-                if ($trace[$i + 1]['class'] === 'HTMLPurifier_Config') {
+                if (isset($trace[$i + 1]['class']) && $trace[$i + 1]['class'] === 'HTMLPurifier_Config') {
                     continue;
                 }
                 $frame = $trace[$i];
diff --git a/lib/htmlpurifier/HTMLPurifier/ConfigSchema.php b/lib/htmlpurifier/HTMLPurifier/ConfigSchema.php
index cc8f4716663..446cdf32046 100644
--- a/lib/htmlpurifier/HTMLPurifier/ConfigSchema.php
+++ b/lib/htmlpurifier/HTMLPurifier/ConfigSchema.php
@@ -100,7 +100,7 @@ class HTMLPurifier_ConfigSchema
      * @param string $key Name of directive
      * @param mixed $default Default value of directive
      * @param string $type Allowed type of the directive. See
-     *      HTMLPurifier_DirectiveDef::$type for allowed values
+     *      HTMLPurifier_VarParser::$types for allowed values
      * @param bool $allow_null Whether or not to allow null values
      */
     public function add($key, $default, $type, $allow_null)
diff --git a/lib/htmlpurifier/HTMLPurifier/ConfigSchema/schema.ser b/lib/htmlpurifier/HTMLPurifier/ConfigSchema/schema.ser
index 371e948f1c7..47bd259b2ef 100644
Binary files a/lib/htmlpurifier/HTMLPurifier/ConfigSchema/schema.ser and b/lib/htmlpurifier/HTMLPurifier/ConfigSchema/schema.ser differ
diff --git a/lib/htmlpurifier/HTMLPurifier/ConfigSchema/schema/AutoFormat.RemoveEmpty.RemoveNbsp.txt b/lib/htmlpurifier/HTMLPurifier/ConfigSchema/schema/AutoFormat.RemoveEmpty.RemoveNbsp.txt
index 5f355d6622e..e557ad21634 100644
--- a/lib/htmlpurifier/HTMLPurifier/ConfigSchema/schema/AutoFormat.RemoveEmpty.RemoveNbsp.txt
+++ b/lib/htmlpurifier/HTMLPurifier/ConfigSchema/schema/AutoFormat.RemoveEmpty.RemoveNbsp.txt
@@ -6,7 +6,7 @@ DEFAULT: false
 <p>
   When enabled, HTML Purifier will treat any elements that contain only
   non-breaking spaces as well as regular whitespace as empty, and remove
-  them when %AutoForamt.RemoveEmpty is enabled.
+  them when %AutoFormat.RemoveEmpty is enabled.
 </p>
 <p>
   See %AutoFormat.RemoveEmpty.RemoveNbsp.Exceptions for a list of elements
diff --git a/lib/htmlpurifier/HTMLPurifier/ConfigSchema/schema/Core.AllowParseManyTags.txt b/lib/htmlpurifier/HTMLPurifier/ConfigSchema/schema/Core.AllowParseManyTags.txt
new file mode 100644
index 00000000000..b4b9b102f16
--- /dev/null
+++ b/lib/htmlpurifier/HTMLPurifier/ConfigSchema/schema/Core.AllowParseManyTags.txt
@@ -0,0 +1,12 @@
+Core.AllowParseManyTags
+TYPE: bool
+DEFAULT: false
+VERSION: 4.10.1
+--DESCRIPTION--
+<p>
+    This directive allows parsing of many nested tags.
+    If you set true, relaxes any hardcoded limit from the parser.
+    However, in that case it may cause a Dos attack.
+    Be careful when enabling it.
+</p>
+--# vim: et sw=4 sts=4
diff --git a/lib/htmlpurifier/HTMLPurifier/ConfigSchema/schema/Core.ColorKeywords.txt b/lib/htmlpurifier/HTMLPurifier/ConfigSchema/schema/Core.ColorKeywords.txt
index f7823982534..fc100868e0e 100644
--- a/lib/htmlpurifier/HTMLPurifier/ConfigSchema/schema/Core.ColorKeywords.txt
+++ b/lib/htmlpurifier/HTMLPurifier/ConfigSchema/schema/Core.ColorKeywords.txt
@@ -3,23 +3,154 @@ TYPE: hash
 VERSION: 2.0.0
 --DEFAULT--
 array (
-  'maroon' => '#800000',
-  'red' => '#FF0000',
-  'orange' => '#FFA500',
-  'yellow' => '#FFFF00',
-  'olive' => '#808000',
-  'purple' => '#800080',
-  'fuchsia' => '#FF00FF',
-  'white' => '#FFFFFF',
-  'lime' => '#00FF00',
-  'green' => '#008000',
-  'navy' => '#000080',
-  'blue' => '#0000FF',
+  'aliceblue' => '#F0F8FF',
+  'antiquewhite' => '#FAEBD7',
   'aqua' => '#00FFFF',
-  'teal' => '#008080',
+  'aquamarine' => '#7FFFD4',
+  'azure' => '#F0FFFF',
+  'beige' => '#F5F5DC',
+  'bisque' => '#FFE4C4',
   'black' => '#000000',
-  'silver' => '#C0C0C0',
+  'blanchedalmond' => '#FFEBCD',
+  'blue' => '#0000FF',
+  'blueviolet' => '#8A2BE2',
+  'brown' => '#A52A2A',
+  'burlywood' => '#DEB887',
+  'cadetblue' => '#5F9EA0',
+  'chartreuse' => '#7FFF00',
+  'chocolate' => '#D2691E',
+  'coral' => '#FF7F50',
+  'cornflowerblue' => '#6495ED',
+  'cornsilk' => '#FFF8DC',
+  'crimson' => '#DC143C',
+  'cyan' => '#00FFFF',
+  'darkblue' => '#00008B',
+  'darkcyan' => '#008B8B',
+  'darkgoldenrod' => '#B8860B',
+  'darkgray' => '#A9A9A9',
+  'darkgrey' => '#A9A9A9',
+  'darkgreen' => '#006400',
+  'darkkhaki' => '#BDB76B',
+  'darkmagenta' => '#8B008B',
+  'darkolivegreen' => '#556B2F',
+  'darkorange' => '#FF8C00',
+  'darkorchid' => '#9932CC',
+  'darkred' => '#8B0000',
+  'darksalmon' => '#E9967A',
+  'darkseagreen' => '#8FBC8F',
+  'darkslateblue' => '#483D8B',
+  'darkslategray' => '#2F4F4F',
+  'darkslategrey' => '#2F4F4F',
+  'darkturquoise' => '#00CED1',
+  'darkviolet' => '#9400D3',
+  'deeppink' => '#FF1493',
+  'deepskyblue' => '#00BFFF',
+  'dimgray' => '#696969',
+  'dimgrey' => '#696969',
+  'dodgerblue' => '#1E90FF',
+  'firebrick' => '#B22222',
+  'floralwhite' => '#FFFAF0',
+  'forestgreen' => '#228B22',
+  'fuchsia' => '#FF00FF',
+  'gainsboro' => '#DCDCDC',
+  'ghostwhite' => '#F8F8FF',
+  'gold' => '#FFD700',
+  'goldenrod' => '#DAA520',
   'gray' => '#808080',
+  'grey' => '#808080',
+  'green' => '#008000',
+  'greenyellow' => '#ADFF2F',
+  'honeydew' => '#F0FFF0',
+  'hotpink' => '#FF69B4',
+  'indianred' => '#CD5C5C',
+  'indigo' => '#4B0082',
+  'ivory' => '#FFFFF0',
+  'khaki' => '#F0E68C',
+  'lavender' => '#E6E6FA',
+  'lavenderblush' => '#FFF0F5',
+  'lawngreen' => '#7CFC00',
+  'lemonchiffon' => '#FFFACD',
+  'lightblue' => '#ADD8E6',
+  'lightcoral' => '#F08080',
+  'lightcyan' => '#E0FFFF',
+  'lightgoldenrodyellow' => '#FAFAD2',
+  'lightgray' => '#D3D3D3',
+  'lightgrey' => '#D3D3D3',
+  'lightgreen' => '#90EE90',
+  'lightpink' => '#FFB6C1',
+  'lightsalmon' => '#FFA07A',
+  'lightseagreen' => '#20B2AA',
+  'lightskyblue' => '#87CEFA',
+  'lightslategray' => '#778899',
+  'lightslategrey' => '#778899',
+  'lightsteelblue' => '#B0C4DE',
+  'lightyellow' => '#FFFFE0',
+  'lime' => '#00FF00',
+  'limegreen' => '#32CD32',
+  'linen' => '#FAF0E6',
+  'magenta' => '#FF00FF',
+  'maroon' => '#800000',
+  'mediumaquamarine' => '#66CDAA',
+  'mediumblue' => '#0000CD',
+  'mediumorchid' => '#BA55D3',
+  'mediumpurple' => '#9370DB',
+  'mediumseagreen' => '#3CB371',
+  'mediumslateblue' => '#7B68EE',
+  'mediumspringgreen' => '#00FA9A',
+  'mediumturquoise' => '#48D1CC',
+  'mediumvioletred' => '#C71585',
+  'midnightblue' => '#191970',
+  'mintcream' => '#F5FFFA',
+  'mistyrose' => '#FFE4E1',
+  'moccasin' => '#FFE4B5',
+  'navajowhite' => '#FFDEAD',
+  'navy' => '#000080',
+  'oldlace' => '#FDF5E6',
+  'olive' => '#808000',
+  'olivedrab' => '#6B8E23',
+  'orange' => '#FFA500',
+  'orangered' => '#FF4500',
+  'orchid' => '#DA70D6',
+  'palegoldenrod' => '#EEE8AA',
+  'palegreen' => '#98FB98',
+  'paleturquoise' => '#AFEEEE',
+  'palevioletred' => '#DB7093',
+  'papayawhip' => '#FFEFD5',
+  'peachpuff' => '#FFDAB9',
+  'peru' => '#CD853F',
+  'pink' => '#FFC0CB',
+  'plum' => '#DDA0DD',
+  'powderblue' => '#B0E0E6',
+  'purple' => '#800080',
+  'rebeccapurple' => '#663399',
+  'red' => '#FF0000',
+  'rosybrown' => '#BC8F8F',
+  'royalblue' => '#4169E1',
+  'saddlebrown' => '#8B4513',
+  'salmon' => '#FA8072',
+  'sandybrown' => '#F4A460',
+  'seagreen' => '#2E8B57',
+  'seashell' => '#FFF5EE',
+  'sienna' => '#A0522D',
+  'silver' => '#C0C0C0',
+  'skyblue' => '#87CEEB',
+  'slateblue' => '#6A5ACD',
+  'slategray' => '#708090',
+  'slategrey' => '#708090',
+  'snow' => '#FFFAFA',
+  'springgreen' => '#00FF7F',
+  'steelblue' => '#4682B4',
+  'tan' => '#D2B48C',
+  'teal' => '#008080',
+  'thistle' => '#D8BFD8',
+  'tomato' => '#FF6347',
+  'turquoise' => '#40E0D0',
+  'violet' => '#EE82EE',
+  'wheat' => '#F5DEB3',
+  'white' => '#FFFFFF',
+  'whitesmoke' => '#F5F5F5',
+  'yellow' => '#FFFF00',
+  'yellowgreen' => '#9ACD32'
 )
 --DESCRIPTION--
 
diff --git a/lib/htmlpurifier/HTMLPurifier/DefinitionCache/Serializer/README b/lib/htmlpurifier/HTMLPurifier/DefinitionCache/Serializer/README
old mode 100644
new mode 100755
diff --git a/lib/htmlpurifier/HTMLPurifier/EntityParser.php b/lib/htmlpurifier/HTMLPurifier/EntityParser.php
index 41059e50f47..4e44fad9cc2 100644
--- a/lib/htmlpurifier/HTMLPurifier/EntityParser.php
+++ b/lib/htmlpurifier/HTMLPurifier/EntityParser.php
@@ -118,7 +118,7 @@ class HTMLPurifier_EntityParser
         $entity = $matches[0];
         $hex_part = @$matches[1];
         $dec_part = @$matches[2];
-        $named_part = empty($matches[3]) ? @$matches[4] : $matches[3];
+        $named_part = empty($matches[3]) ? (empty($matches[4]) ? "" : $matches[4]) : $matches[3];
         if ($hex_part !== NULL && $hex_part !== "") {
             return HTMLPurifier_Encoder::unichr(hexdec($hex_part));
         } elseif ($dec_part !== NULL && $dec_part !== "") {
diff --git a/lib/htmlpurifier/HTMLPurifier/HTMLModule.php b/lib/htmlpurifier/HTMLPurifier/HTMLModule.php
index 9877f9efe90..a94b8ea4cf5 100644
--- a/lib/htmlpurifier/HTMLPurifier/HTMLModule.php
+++ b/lib/htmlpurifier/HTMLPurifier/HTMLModule.php
@@ -132,9 +132,9 @@ class HTMLPurifier_HTMLModule
      * @param string $element Name of element to add
      * @param string|bool $type What content set should element be registered to?
      *              Set as false to skip this step.
-     * @param string $contents Allowed children in form of:
+     * @param string|HTMLPurifier_ChildDef $contents Allowed children in form of:
      *              "$content_model_type: $content_model"
-     * @param array $attr_includes What attribute collections to register to
+     * @param array|string $attr_includes What attribute collections to register to
      *              element?
      * @param array $attr What unique attributes does the element define?
      * @see HTMLPurifier_ElementDef:: for in-depth descriptions of these parameters.
diff --git a/lib/htmlpurifier/HTMLPurifier/HTMLModule/SafeScripting.php b/lib/htmlpurifier/HTMLPurifier/HTMLModule/SafeScripting.php
index 6e9113cb59c..22669a6cdcf 100644
--- a/lib/htmlpurifier/HTMLPurifier/HTMLModule/SafeScripting.php
+++ b/lib/htmlpurifier/HTMLPurifier/HTMLModule/SafeScripting.php
@@ -23,13 +23,13 @@ class HTMLPurifier_HTMLModule_SafeScripting extends HTMLPurifier_HTMLModule
         $script = $this->addElement(
             'script',
             'Inline',
-            'Empty',
+            'Optional:', // Not `Empty` to not allow to autoclose the <script /> tag @see https://www.w3.org/TR/html4/interact/scripts.html
             null,
             array(
                 // While technically not required by the spec, we're forcing
                 // it to this value.
                 'type' => 'Enum#text/javascript',
-                'src*' => new HTMLPurifier_AttrDef_Enum(array_keys($allowed))
+                'src*' => new HTMLPurifier_AttrDef_Enum(array_keys($allowed), /*case sensitive*/ true)
             )
         );
         $script->attr_transform_pre[] =
diff --git a/lib/htmlpurifier/HTMLPurifier/Language/messages/en-x-test.php b/lib/htmlpurifier/HTMLPurifier/Language/messages/en-x-test.php
index e6a174a0753..83280543f18 100644
--- a/lib/htmlpurifier/HTMLPurifier/Language/messages/en-x-test.php
+++ b/lib/htmlpurifier/HTMLPurifier/Language/messages/en-x-test.php
@@ -8,4 +8,6 @@ $messages = array(
     'HTMLPurifier' => 'HTML Purifier X'
 );
 
+$errorNames = array();
+
 // vim: et sw=4 sts=4
diff --git a/lib/htmlpurifier/HTMLPurifier/Language/messages/en-x-testmini.php b/lib/htmlpurifier/HTMLPurifier/Language/messages/en-x-testmini.php
index ed8560fd586..b6d1c99eadc 100644
--- a/lib/htmlpurifier/HTMLPurifier/Language/messages/en-x-testmini.php
+++ b/lib/htmlpurifier/HTMLPurifier/Language/messages/en-x-testmini.php
@@ -9,4 +9,6 @@ $messages = array(
     'HTMLPurifier' => 'HTML Purifier XNone'
 );
 
+$errorNames = array();
+
 // vim: et sw=4 sts=4
diff --git a/lib/htmlpurifier/HTMLPurifier/Lexer/DOMLex.php b/lib/htmlpurifier/HTMLPurifier/Lexer/DOMLex.php
index de352589c79..ffa167c09a0 100644
--- a/lib/htmlpurifier/HTMLPurifier/Lexer/DOMLex.php
+++ b/lib/htmlpurifier/HTMLPurifier/Lexer/DOMLex.php
@@ -68,8 +68,18 @@ class HTMLPurifier_Lexer_DOMLex extends HTMLPurifier_Lexer
         $doc = new DOMDocument();
         $doc->encoding = 'UTF-8'; // theoretically, the above has this covered
 
+        $options = 0;
+        if ($config->get('Core.AllowParseManyTags') && defined('LIBXML_PARSEHUGE')) {
+            $options |= LIBXML_PARSEHUGE;
+        }
+
         set_error_handler(array($this, 'muteErrorHandler'));
-        $doc->loadHTML($html);
+        // loadHTML() fails on PHP 5.3 when second parameter is given
+        if ($options) {
+            $doc->loadHTML($html, $options);
+        } else {
+            $doc->loadHTML($html);
+        }
         restore_error_handler();
 
         $body = $doc->getElementsByTagName('html')->item(0)-> // <html>
@@ -133,11 +143,11 @@ class HTMLPurifier_Lexer_DOMLex extends HTMLPurifier_Lexer
      */
     protected function getTagName($node)
     {
-        if (property_exists($node, 'tagName')) {
+        if (isset($node->tagName)) {
             return $node->tagName;
-        } else if (property_exists($node, 'nodeName')) {
+        } else if (isset($node->nodeName)) {
             return $node->nodeName;
-        } else if (property_exists($node, 'localName')) {
+        } else if (isset($node->localName)) {
             return $node->localName;
         }
         return null;
@@ -150,11 +160,11 @@ class HTMLPurifier_Lexer_DOMLex extends HTMLPurifier_Lexer
      */
     protected function getData($node)
     {
-        if (property_exists($node, 'data')) {
+        if (isset($node->data)) {
             return $node->data;
-        } else if (property_exists($node, 'nodeValue')) {
+        } else if (isset($node->nodeValue)) {
             return $node->nodeValue;
-        } else if (property_exists($node, 'textContent')) {
+        } else if (isset($node->textContent)) {
             return $node->textContent;
         }
         return null;
diff --git a/lib/htmlpurifier/HTMLPurifier/Printer/ConfigForm.php b/lib/htmlpurifier/HTMLPurifier/Printer/ConfigForm.php
index 3bc417366f2..8897002ea36 100644
--- a/lib/htmlpurifier/HTMLPurifier/Printer/ConfigForm.php
+++ b/lib/htmlpurifier/HTMLPurifier/Printer/ConfigForm.php
@@ -48,7 +48,7 @@ class HTMLPurifier_Printer_ConfigForm extends HTMLPurifier_Printer
         $this->compress = $compress;
         // initialize sub-printers
         $this->fields[0] = new HTMLPurifier_Printer_ConfigForm_default();
-        $this->fields[HTMLPurifier_VarParser::BOOL] = new HTMLPurifier_Printer_ConfigForm_bool();
+        $this->fields[HTMLPurifier_VarParser::C_BOOL] = new HTMLPurifier_Printer_ConfigForm_bool();
     }
 
     /**
@@ -339,7 +339,7 @@ class HTMLPurifier_Printer_ConfigForm_default extends HTMLPurifier_Printer
                     $value = '';
             }
         }
-        if ($type === HTMLPurifier_VarParser::MIXED) {
+        if ($type === HTMLPurifier_VarParser::C_MIXED) {
             return 'Not supported';
             $value = serialize($value);
         }
diff --git a/lib/htmlpurifier/HTMLPurifier/VarParser.php b/lib/htmlpurifier/HTMLPurifier/VarParser.php
index 4bf7771a1fb..6a9ef71582d 100644
--- a/lib/htmlpurifier/HTMLPurifier/VarParser.php
+++ b/lib/htmlpurifier/HTMLPurifier/VarParser.php
@@ -7,34 +7,34 @@
 class HTMLPurifier_VarParser
 {
 
-    const STRING = 1;
+    const C_STRING = 1;
     const ISTRING = 2;
     const TEXT = 3;
     const ITEXT = 4;
-    const INT = 5;
-    const FLOAT = 6;
-    const BOOL = 7;
+    const C_INT = 5;
+    const C_FLOAT = 6;
+    const C_BOOL = 7;
     const LOOKUP = 8;
     const ALIST = 9;
     const HASH = 10;
-    const MIXED = 11;
+    const C_MIXED = 11;
 
     /**
      * Lookup table of allowed types. Mainly for backwards compatibility, but
      * also convenient for transforming string type names to the integer constants.
      */
     public static $types = array(
-        'string' => self::STRING,
+        'string' => self::C_STRING,
         'istring' => self::ISTRING,
         'text' => self::TEXT,
         'itext' => self::ITEXT,
-        'int' => self::INT,
-        'float' => self::FLOAT,
-        'bool' => self::BOOL,
+        'int' => self::C_INT,
+        'float' => self::C_FLOAT,
+        'bool' => self::C_BOOL,
         'lookup' => self::LOOKUP,
         'list' => self::ALIST,
         'hash' => self::HASH,
-        'mixed' => self::MIXED
+        'mixed' => self::C_MIXED
     );
 
     /**
@@ -42,7 +42,7 @@ class HTMLPurifier_VarParser
      * allowed value lists.
      */
     public static $stringTypes = array(
-        self::STRING => true,
+        self::C_STRING => true,
         self::ISTRING => true,
         self::TEXT => true,
         self::ITEXT => true,
@@ -74,7 +74,7 @@ class HTMLPurifier_VarParser
         // These are basic checks, to make sure nothing horribly wrong
         // happened in our implementations.
         switch ($type) {
-            case (self::STRING):
+            case (self::C_STRING):
             case (self::ISTRING):
             case (self::TEXT):
             case (self::ITEXT):
@@ -85,17 +85,17 @@ class HTMLPurifier_VarParser
                     $var = strtolower($var);
                 }
                 return $var;
-            case (self::INT):
+            case (self::C_INT):
                 if (!is_int($var)) {
                     break;
                 }
                 return $var;
-            case (self::FLOAT):
+            case (self::C_FLOAT):
                 if (!is_float($var)) {
                     break;
                 }
                 return $var;
-            case (self::BOOL):
+            case (self::C_BOOL):
                 if (!is_bool($var)) {
                     break;
                 }
@@ -119,7 +119,7 @@ class HTMLPurifier_VarParser
                     }
                 }
                 return $var;
-            case (self::MIXED):
+            case (self::C_MIXED):
                 return $var;
             default:
                 $this->errorInconsistent(get_class($this), $type);
diff --git a/lib/htmlpurifier/HTMLPurifier/VarParser/Flexible.php b/lib/htmlpurifier/HTMLPurifier/VarParser/Flexible.php
index b2ed860ac07..4ec648b4a14 100644
--- a/lib/htmlpurifier/HTMLPurifier/VarParser/Flexible.php
+++ b/lib/htmlpurifier/HTMLPurifier/VarParser/Flexible.php
@@ -23,23 +23,23 @@ class HTMLPurifier_VarParser_Flexible extends HTMLPurifier_VarParser
             // Note: if code "breaks" from the switch, it triggers a generic
             // exception to be thrown. Specific errors can be specifically
             // done here.
-            case self::MIXED:
+            case self::C_MIXED:
             case self::ISTRING:
-            case self::STRING:
+            case self::C_STRING:
             case self::TEXT:
             case self::ITEXT:
                 return $var;
-            case self::INT:
+            case self::C_INT:
                 if (is_string($var) && ctype_digit($var)) {
                     $var = (int)$var;
                 }
                 return $var;
-            case self::FLOAT:
+            case self::C_FLOAT:
                 if ((is_string($var) && is_numeric($var)) || is_int($var)) {
                     $var = (float)$var;
                 }
                 return $var;
-            case self::BOOL:
+            case self::C_BOOL:
                 if (is_int($var) && ($var === 0 || $var === 1)) {
                     $var = (bool)$var;
                 } elseif (is_string($var)) {
diff --git a/lib/htmlpurifier/readme_moodle.txt b/lib/htmlpurifier/readme_moodle.txt
index 1195367485d..6935b7081ec 100644
--- a/lib/htmlpurifier/readme_moodle.txt
+++ b/lib/htmlpurifier/readme_moodle.txt
@@ -1,23 +1,20 @@
-Description of HTML Purifier v4.10.0 library import into Moodle
+Description of HTML Purifier v4.12.0 library import into Moodle
 
 * Make new (or delete contents of) /lib/htmlpurifier/
 * Copy everything from /library/ folder to /lib/htmlpurifier/
 * Copy CREDITS, LICENSE from root folder to /lib/htmlpurifier/
 * Delete unused files:
     HTMLPurifier.auto.php
-    HTMLPurifier.func.php
-    HTMLPurifier.kses.php
     HTMLPurifier.autoload.php
-    HTMLPurifier.composer.php
-    HTMLPurifier.includes.php
-    HTMLPurifier.path.php
     HTMLPurifier.autoload-legacy.php
+    HTMLPurifier.composer.php
+    HTMLPurifier.func.php
+    HTMLPurifier.includes.php
+    HTMLPurifier.kses.php
+    HTMLPurifier.path.php
 * add locallib.php with Moodle specific extensions to /lib/htmlpurifier/
 * add this readme_moodle.txt to /lib/htmlpurifier/
 
 Modifications:
 (verify if we need to apply them on every upgrade, remove when not needed)
-* MDL-60337 use correct IDN variant for converting domain names to ascii
-  Check status of https://github.com/ezyang/htmlpurifier/pull/148
-* MDL-67030 applied https://github.com/ezyang/htmlpurifier/pull/224 towards
-  php74 compatibility.
+(No modification was needed)
\ No newline at end of file
diff --git a/lib/thirdpartylibs.xml b/lib/thirdpartylibs.xml
index 5630e29d6a3..16b39589cfa 100644
--- a/lib/thirdpartylibs.xml
+++ b/lib/thirdpartylibs.xml
@@ -39,7 +39,7 @@
     <location>htmlpurifier</location>
     <name>HTML Purifier</name>
     <license>LGPL</license>
-    <version>4.10.0</version>
+    <version>4.12.0</version>
     <licenseversion>2.1+</licenseversion>
   </library>
   <library>