diff --git src/wp-includes/customize/class-wp-customize-site-icon-control.php src/wp-includes/customize/class-wp-customize-site-icon-control.php
index d21395c39c..e57e955be7 100644
--- src/wp-includes/customize/class-wp-customize-site-icon-control.php
+++ src/wp-includes/customize/class-wp-customize-site-icon-control.php
@@ -68,7 +68,7 @@ class WP_Customize_Site_Icon_Control extends WP_Customize_Cropped_Image_Control
 							<div class="favicon">
 								<img src="{{ data.attachment.sizes.full ? data.attachment.sizes.full.url : data.attachment.url }}" alt="<?php esc_attr_e( 'Preview as a browser icon' ); ?>"/>
 							</div>
-							<span class="browser-title" aria-hidden="true"><# print( '<?php bloginfo( 'name' ); ?>' ) #></span>
+							<span class="browser-title" aria-hidden="true"><# print( '<?php str_replace( '\\', '\\\\', get_bloginfo( 'name' ) ); ?>' ) #></span>
 						</div>
 						<img class="app-icon-preview" src="{{ data.attachment.sizes.full ? data.attachment.sizes.full.url : data.attachment.url }}" alt="<?php esc_attr_e( 'Preview as an app icon' ); ?>"/>
 					</div>
diff --git src/wp-includes/media-template.php src/wp-includes/media-template.php
index 43053edfa9..637feb5187 100644
--- src/wp-includes/media-template.php
+++ src/wp-includes/media-template.php
@@ -1448,7 +1448,7 @@ function wp_print_media_templates() {
 			<div class="favicon">
 				<img id="preview-favicon" src="{{ data.url }}" alt="<?php esc_attr_e( 'Preview as a browser icon' ); ?>"/>
 			</div>
-			<span class="browser-title" aria-hidden="true"><# print( '<?php bloginfo( 'name' ); ?>' ) #></span>
+			<span class="browser-title" aria-hidden="true"><# print( '<?php str_replace( '\\', '\\\\', get_bloginfo( 'name' ) ); ?>' ) #></span>
 		</div>
 
 		<strong aria-hidden="true"><?php _e( 'As an app icon' ); ?></strong>