diff --git a/wp-includes/sodium_compat/autoload-php7.php b/wp-includes/sodium_compat/autoload-php7.php
new file mode 100644
index 0000000000..482486043b
--- /dev/null
+++ b/wp-includes/sodium_compat/autoload-php7.php
@@ -0,0 +1,31 @@
+<?php
+/*
+ This file should only ever be loaded on PHP 7+
+ */
+if (PHP_VERSION_ID < 70000) {
+    return;
+}
+
+spl_autoload_register(function ($class) {
+    $namespace = 'ParagonIE_Sodium_';
+    // Does the class use the namespace prefix?
+    $len = strlen($namespace);
+    if (strncmp($namespace, $class, $len) !== 0) {
+        // no, move to the next registered autoloader
+        return false;
+    }
+
+    // Get the relative class name
+    $relative_class = substr($class, $len);
+
+    // Replace the namespace prefix with the base directory, replace namespace
+    // separators with directory separators in the relative class name, append
+    // with .php
+    $file = dirname(__FILE__) . '/src/' . str_replace('_', '/', $relative_class) . '.php';
+    // if the file exists, require it
+    if (file_exists($file)) {
+        require_once $file;
+        return true;
+    }
+    return false;
+});
diff --git a/wp-includes/sodium_compat/autoload.php b/wp-includes/sodium_compat/autoload.php
index aa6ef8535b..d7c777b008 100644
--- a/wp-includes/sodium_compat/autoload.php
+++ b/wp-includes/sodium_compat/autoload.php
@@ -1,43 +1,49 @@
 <?php
 
-if (!is_callable('sodiumCompatAutoloader')) {
-    /**
-     * Sodium_Compat autoloader.
-     *
-     * @param string $class Class name to be autoloaded.
-     *
-     * @return bool         Stop autoloading?
-     */
-    function sodiumCompatAutoloader($class)
-    {
-        $namespace = 'ParagonIE_Sodium_';
-        // Does the class use the namespace prefix?
-        $len = strlen($namespace);
-        if (strncmp($namespace, $class, $len) !== 0) {
-            // no, move to the next registered autoloader
+if (PHP_VERSION_ID < 70000) {
+    if (!is_callable('sodiumCompatAutoloader')) {
+        /**
+         * Sodium_Compat autoloader.
+         *
+         * @param string $class Class name to be autoloaded.
+         *
+         * @return bool         Stop autoloading?
+         */
+        function sodiumCompatAutoloader($class)
+        {
+            $namespace = 'ParagonIE_Sodium_';
+            // Does the class use the namespace prefix?
+            $len = strlen($namespace);
+            if (strncmp($namespace, $class, $len) !== 0) {
+                // no, move to the next registered autoloader
+                return false;
+            }
+
+            // Get the relative class name
+            $relative_class = substr($class, $len);
+
+            // Replace the namespace prefix with the base directory, replace namespace
+            // separators with directory separators in the relative class name, append
+            // with .php
+            $file = dirname(__FILE__) . '/src/' . str_replace('_', '/', $relative_class) . '.php';
+            // if the file exists, require it
+            if (file_exists($file)) {
+                require_once $file;
+                return true;
+            }
             return false;
         }
 
-        // Get the relative class name
-        $relative_class = substr($class, $len);
-
-        // Replace the namespace prefix with the base directory, replace namespace
-        // separators with directory separators in the relative class name, append
-        // with .php
-        $file = dirname(__FILE__) . '/src/' . str_replace('_', '/', $relative_class) . '.php';
-        // if the file exists, require it
-        if (file_exists($file)) {
-            require_once $file;
-            return true;
-        }
-        return false;
+        // Now that we have an autoloader, let's register it!
+        spl_autoload_register('sodiumCompatAutoloader');
     }
-
-    // Now that we have an autoloader, let's register it!
-    spl_autoload_register('sodiumCompatAutoloader');
+} else {
+    require_once dirname(__FILE__) . '/autoload-php7.php';
 }
 
-require_once dirname(__FILE__) . '/src/SodiumException.php';
+if (!class_exists('SodiumException', false)) {
+    require_once dirname(__FILE__) . '/src/SodiumException.php';
+}
 if (PHP_VERSION_ID >= 50300) {
     // Namespaces didn't exist before 5.3.0, so don't even try to use this
     // unless PHP >= 5.3.0
diff --git a/wp-includes/sodium_compat/lib/php72compat.php b/wp-includes/sodium_compat/lib/php72compat.php
index c39ec26a88..fa8c37299f 100644
--- a/wp-includes/sodium_compat/lib/php72compat.php
+++ b/wp-includes/sodium_compat/lib/php72compat.php
@@ -26,6 +26,10 @@ foreach (array(
     'CRYPTO_AEAD_CHACHA20POLY1305_IETF_NSECBYTES',
     'CRYPTO_AEAD_CHACHA20POLY1305_IETF_NPUBBYTES',
     'CRYPTO_AEAD_CHACHA20POLY1305_IETF_ABYTES',
+    'CRYPTO_AEAD_XCHACHA20POLY1305_IETF_KEYBYTES',
+    'CRYPTO_AEAD_XCHACHA20POLY1305_IETF_NSECBYTES',
+    'CRYPTO_AEAD_XCHACHA20POLY1305_IETF_NPUBBYTES',
+    'CRYPTO_AEAD_XCHACHA20POLY1305_IETF_ABYTES',
     'CRYPTO_AUTH_BYTES',
     'CRYPTO_AUTH_KEYBYTES',
     'CRYPTO_BOX_SEALBYTES',
@@ -62,6 +66,12 @@ foreach (array(
     'CRYPTO_PWHASH_OPSLIMIT_MODERATE',
     'CRYPTO_PWHASH_MEMLIMIT_SENSITIVE',
     'CRYPTO_PWHASH_OPSLIMIT_SENSITIVE',
+    'CRYPTO_PWHASH_SCRYPTSALSA208SHA256_SALTBYTES',
+    'CRYPTO_PWHASH_SCRYPTSALSA208SHA256_STRPREFIX',
+    'CRYPTO_PWHASH_SCRYPTSALSA208SHA256_MEMLIMIT_INTERACTIVE',
+    'CRYPTO_PWHASH_SCRYPTSALSA208SHA256_OPSLIMIT_INTERACTIVE',
+    'CRYPTO_PWHASH_SCRYPTSALSA208SHA256_MEMLIMIT_SENSITIVE',
+    'CRYPTO_PWHASH_SCRYPTSALSA208SHA256_OPSLIMIT_SENSITIVE',
     'CRYPTO_SCALARMULT_BYTES',
     'CRYPTO_SCALARMULT_SCALARBYTES',
     'CRYPTO_SHORTHASH_BYTES',
@@ -84,6 +94,8 @@ foreach (array(
     'CRYPTO_SIGN_KEYPAIRBYTES',
     'CRYPTO_STREAM_KEYBYTES',
     'CRYPTO_STREAM_NONCEBYTES',
+    'LIBRARY_MAJOR_VERSION',
+    'LIBRARY_MINOR_VERSION',
     'LIBRARY_VERSION_MAJOR',
     'LIBRARY_VERSION_MINOR',
     'VERSION_STRING'
diff --git a/wp-includes/sodium_compat/src/Compat.php b/wp-includes/sodium_compat/src/Compat.php
index e49133fe05..ff76adbcb0 100644
--- a/wp-includes/sodium_compat/src/Compat.php
+++ b/wp-includes/sodium_compat/src/Compat.php
@@ -44,6 +44,8 @@ class ParagonIE_Sodium_Compat
      */
     public static $fastMult = false;
 
+    const LIBRARY_MAJOR_VERSION = 9;
+    const LIBRARY_MINOR_VERSION = 1;
     const LIBRARY_VERSION_MAJOR = 9;
     const LIBRARY_VERSION_MINOR = 1;
     const VERSION_STRING = 'polyfill-1.0.8';
@@ -3117,15 +3119,14 @@ class ParagonIE_Sodium_Compat
      * with (sans pwhash and memzero).
      *
      * @return int
-     * @psalm-suppress MixedInferredReturnType
-     * @psalm-suppress UndefinedFunction
      */
     public static function library_version_major()
     {
-        if (self::useNewSodiumAPI()) {
-            return sodium_library_version_major();
+        if (self::useNewSodiumAPI() && defined('SODIUM_LIBRARY_MAJOR_VERSION')) {
+            return SODIUM_LIBRARY_MAJOR_VERSION;
         }
         if (self::use_fallback('library_version_major')) {
+            /** @psalm-suppress UndefinedFunction */
             return (int) call_user_func('\\Sodium\\library_version_major');
         }
         return self::LIBRARY_VERSION_MAJOR;
@@ -3136,15 +3137,14 @@ class ParagonIE_Sodium_Compat
      * with (sans pwhash and memzero).
      *
      * @return int
-     * @psalm-suppress MixedInferredReturnType
-     * @psalm-suppress UndefinedFunction
      */
     public static function library_version_minor()
     {
-        if (self::useNewSodiumAPI()) {
-            return sodium_library_version_minor();
+        if (self::useNewSodiumAPI() && defined('SODIUM_LIBRARY_MINOR_VERSION')) {
+            return SODIUM_LIBRARY_MINOR_VERSION;
         }
         if (self::use_fallback('library_version_minor')) {
+            /** @psalm-suppress UndefinedFunction */
             return (int) call_user_func('\\Sodium\\library_version_minor');
         }
         return self::LIBRARY_VERSION_MINOR;
diff --git a/wp-includes/sodium_compat/src/File.php b/wp-includes/sodium_compat/src/File.php
index a28df9ffa9..b4948db36c 100644
--- a/wp-includes/sodium_compat/src/File.php
+++ b/wp-includes/sodium_compat/src/File.php
@@ -141,7 +141,9 @@ class ParagonIE_Sodium_File extends ParagonIE_Sodium_Core_Util
             ParagonIE_Sodium_Compat::memzero($nonce);
             ParagonIE_Sodium_Compat::memzero($ephKeypair);
         } catch (SodiumException $ex) {
-            unset($ephKeypair);
+            if (isset($ephKeypair)) {
+                unset($ephKeypair);
+            }
         }
         return $res;
     }
@@ -328,7 +330,9 @@ class ParagonIE_Sodium_File extends ParagonIE_Sodium_Core_Util
             ParagonIE_Sodium_Compat::memzero($nonce);
             ParagonIE_Sodium_Compat::memzero($ephKeypair);
         } catch (SodiumException $ex) {
-            unset($ephKeypair);
+            if (isset($ephKeypair)) {
+                unset($ephKeypair);
+            }
         }
         return $res;
     }
diff --git a/wp-includes/version.php b/wp-includes/version.php
index c89b4ad65e..089215be4e 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.6-alpha-49055';
+$wp_version = '5.6-alpha-49056';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.