diff --git a/wp-includes/blocks/rss.php b/wp-includes/blocks/rss.php
index f1b7f3f19d..44a465ea61 100644
--- a/wp-includes/blocks/rss.php
+++ b/wp-includes/blocks/rss.php
@@ -16,7 +16,7 @@ function render_block_core_rss( $attributes ) {
 	$rss = fetch_feed( $attributes['feedURL'] );
 
 	if ( is_wp_error( $rss ) ) {
-		return '<div class="components-placeholder"><div class="notice notice-error"><strong>' . __( 'RSS Error:' ) . '</strong> ' . $rss->get_error_message() . '</div></div>';
+		return '<div class="components-placeholder"><div class="notice notice-error"><strong>' . __( 'RSS Error:' ) . '</strong> ' . esc_html( $rss->get_error_message() ) . '</div></div>';
 	}
 
 	if ( ! $rss->get_item_quantity() ) {
@@ -48,8 +48,8 @@ function render_block_core_rss( $attributes ) {
 			if ( $date ) {
 				$date = sprintf(
 					'<time datetime="%1$s" class="wp-block-rss__item-publish-date">%2$s</time> ',
-					date_i18n( get_option( 'c' ), $date ),
-					date_i18n( get_option( 'date_format' ), $date )
+					esc_attr( date_i18n( get_option( 'c' ), $date ) ),
+					esc_attr( date_i18n( get_option( 'date_format' ), $date ) )
 				);
 			}
 		}