diff --git a/src/wp-admin/includes/update.php b/src/wp-admin/includes/update.php
index 6661d44afd..72672c687f 100644
--- a/src/wp-admin/includes/update.php
+++ b/src/wp-admin/includes/update.php
@@ -231,7 +231,7 @@ function update_nag() {
 		return false;
 
 	if ( current_user_can('update_core') ) {
-		$msg = sprintf( __('<a href="https://codex.wordpress.org/Version_%1$s">WordPress %1$s</a> is available! <a href="%2$s">Please update now</a>.'), $cur->current, network_admin_url( 'update-core.php' ) );
+		$msg = sprintf( __( '<a href="https://codex.wordpress.org/Version_%1$s">WordPress %1$s</a> is available! <a href="%2$s" aria-label="Please update WordPress now">Please update now</a>.' ), $cur->current, network_admin_url( 'update-core.php' ) );
 	} else {
 		$msg = sprintf( __('<a href="https://codex.wordpress.org/Version_%1$s">WordPress %1$s</a> is available! Please notify the site administrator.'), $cur->current );
 	}
@@ -338,11 +338,30 @@ function wp_plugin_update_row( $file, $plugin_data ) {
 		echo '<tr class="plugin-update-tr' . $active_class . '" id="' . esc_attr( $r->slug . '-update' ) . '" data-slug="' . esc_attr( $r->slug ) . '" data-plugin="' . esc_attr( $file ) . '"><td colspan="' . esc_attr( $wp_list_table->get_column_count() ) . '" class="plugin-update colspanchange"><div class="update-message">';
 
 		if ( ! current_user_can( 'update_plugins' ) ) {
-			printf( __('There is a new version of %1$s available. <a href="%2$s" class="thickbox" title="%3$s">View version %4$s details</a>.'), $plugin_name, esc_url($details_url), esc_attr($plugin_name), $r->new_version );
-		} elseif ( empty($r->package) ) {
-			printf( __('There is a new version of %1$s available. <a href="%2$s" class="thickbox" title="%3$s">View version %4$s details</a>. <em>Automatic update is unavailable for this plugin.</em>'), $plugin_name, esc_url($details_url), esc_attr($plugin_name), $r->new_version );
+			/* translators: 1: plugin name, 2: details URL, 3: escaped plugin name, 4: version number */
+			printf( __( 'There is a new version of %1$s available. <a href="%2$s" class="thickbox" aria-label="View %3$s version %4$s details">View version %4$s details</a>.' ),
+				$plugin_name,
+				esc_url( $details_url ),
+				esc_attr( $plugin_name ),
+				$r->new_version
+			);
+		} elseif ( empty( $r->package ) ) {
+			/* translators: 1: plugin name, 2: details URL, 3: escaped plugin name, 4: version number */
+			printf( __( 'There is a new version of %1$s available. <a href="%2$s" class="thickbox" aria-label="View %3$s version %4$s details">View version %4$s details</a>. <em>Automatic update is unavailable for this plugin.</em>' ),
+				$plugin_name,
+				esc_url( $details_url ),
+				esc_attr( $plugin_name ),
+				$r->new_version
+			);
 		} else {
-			printf( __( 'There is a new version of %1$s available. <a href="%2$s" class="thickbox" title="%3$s">View version %4$s details</a> or <a href="%5$s" class="update-link">update now</a>.' ), $plugin_name, esc_url( $details_url ), esc_attr( $plugin_name ), $r->new_version, wp_nonce_url( self_admin_url( 'update.php?action=upgrade-plugin&plugin=' ) . $file, 'upgrade-plugin_' . $file ) );
+			/* translators: 1: plugin name, 2: details URL, 3: escaped plugin name, 4: version number, 5: update URL */
+			printf( __( 'There is a new version of %1$s available. <a href="%2$s" class="thickbox" aria-label="View %3$s version %4$s details">View version %4$s details</a> or <a href="%5$s" class="update-link" aria-label="update %3$s now">update now</a>.' ),
+				$plugin_name,
+				esc_url( $details_url ),
+				esc_attr( $plugin_name ),
+				$r->new_version,
+				wp_nonce_url( self_admin_url( 'update.php?action=upgrade-plugin&plugin=' ) . $file, 'upgrade-plugin_' . $file )
+			);
 		}
 		/**
 		 * Fires at the end of the update message container in each
@@ -439,11 +458,30 @@ function wp_theme_update_row( $theme_key, $theme ) {
 
 	echo '<tr class="plugin-update-tr"><td colspan="' . $wp_list_table->get_column_count() . '" class="plugin-update colspanchange"><div class="update-message">';
 	if ( ! current_user_can('update_themes') ) {
-		printf( __('There is a new version of %1$s available. <a href="%2$s" class="thickbox" title="%3$s">View version %4$s details</a>.'), $theme['Name'], esc_url($details_url), esc_attr($theme['Name']), $r->new_version );
+		/* translators: 1: theme name, 2: details URL, 3: escaped theme name, 4: version number */
+		printf( __( 'There is a new version of %1$s available. <a href="%2$s" class="thickbox" aria-label="View %3$s version %4$s details">View version %4$s details</a>.'),
+			$theme['Name'],
+			esc_url( $details_url ),
+			esc_attr( $theme['Name'] ),
+			$r->new_version
+		);
 	} elseif ( empty( $r['package'] ) ) {
-		printf( __('There is a new version of %1$s available. <a href="%2$s" class="thickbox" title="%3$s">View version %4$s details</a>. <em>Automatic update is unavailable for this theme.</em>'), $theme['Name'], esc_url($details_url), esc_attr($theme['Name']), $r['new_version'] );
+		/* translators: 1: theme name, 2: details URL, 3: escaped theme name, 4: version number */
+		printf( __( 'There is a new version of %1$s available. <a href="%2$s" class="thickbox" aria-label="View %3$s version %4$s details">View version %4$s details</a>. <em>Automatic update is unavailable for this theme.</em>' ),
+			$theme['Name'],
+			esc_url( $details_url ),
+			esc_attr( $theme['Name'] ),
+			$r['new_version']
+		);
 	} else {
-		printf( __('There is a new version of %1$s available. <a href="%2$s" class="thickbox" title="%3$s">View version %4$s details</a> or <a href="%5$s">update now</a>.'), $theme['Name'], esc_url($details_url), esc_attr($theme['Name']), $r['new_version'], wp_nonce_url( self_admin_url('update.php?action=upgrade-theme&theme=') . $theme_key, 'upgrade-theme_' . $theme_key) );
+		/* translators: 1: theme name, 2: details URL, 3: escaped theme name, 4: version number, 5: update URL */
+		printf( __( 'There is a new version of %1$s available. <a href="%2$s" class="thickbox" aria-label="View %3$s version %4$s details">View version %4$s details</a> or <a href="%5$s" aria-label="update %3$s now">update now</a>.' ),
+			$theme['Name'],
+			esc_url( $details_url ),
+			esc_attr( $theme['Name'] ),
+			$r['new_version'],
+			wp_nonce_url( self_admin_url( 'update.php?action=upgrade-theme&theme=' ) . $theme_key, 'upgrade-theme_' . $theme_key )
+		);
 	}
 	/**
 	 * Fires at the end of the update message container in each