diff --git a/readme.html b/readme.html
index bb0d615d90..f3f7bb6da8 100644
--- a/readme.html
+++ b/readme.html
@@ -9,7 +9,7 @@
 <body>
 <h1 id="logo">
 	<a href="https://wordpress.org/"><img alt="WordPress" src="wp-admin/images/wordpress-logo.png" /></a>
-	<br /> Version 4.5.8
+	<br /> Version 4.5.9
 </h1>
 <p style="text-align: center">Semantic Personal Publishing Platform</p>
 
diff --git a/wp-admin/about.php b/wp-admin/about.php
index 9af8b28fb0..7a94b8dfdf 100644
--- a/wp-admin/about.php
+++ b/wp-admin/about.php
@@ -40,6 +40,9 @@ include( ABSPATH . 'wp-admin/admin-header.php' );
 
 		<div class="changelog point-releases">
 			<h3><?php _e( 'Maintenance and Security Releases' ); ?></h3>
+			<p><?php printf( __( '<strong>Version %s</strong> addressed some security issues.' ), '4.5.9' ); ?>
+				<?php printf( __( 'For more information, see <a href="%s">the release notes</a>.' ), 'https://codex.wordpress.org/Version_4.5.9' ); ?>
+			</p>
 			<p><?php printf( _n( '<strong>Version %1$s</strong> addressed %2$s bug.',
 					'<strong>Version %1$s</strong> addressed %2$s bugs.', 1 ), '4.5.8', number_format_i18n( 1 ) ); ?>
 				<?php printf( __( 'For more information, see <a href="%s">the release notes</a>.' ), 'https://codex.wordpress.org/Version_4.5.8' ); ?>
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 78b62905bd..b6287b1168 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.5.8';
+$wp_version = '4.5.9';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.
