@@ -1804,7 +1804,7 @@ function wp_kses_no_null( $content, $options = null ) {
 		$options = array( 'slash_zero' => 'remove' );
 	}
 
-	$content = preg_replace( '/[\x00-\x08\x0B\x0C\x0E-\x1F]/', '', $content );
+	$content = preg_replace('/[\x00-\x08\x0B\x0C\x0E-\x1F]/', '', $content ?? '');
 	if ( 'remove' === $options['slash_zero'] ) {
 		$content = preg_replace( '/\\\\+0+/', '', $content );
 	}
Original file line number	Diff line number	Diff line change
`@@ -1804,7 +1804,7 @@ function wp_kses_no_null( $content, $options = null ) {`
`1804`	`1804`	`$options = array( 'slash_zero' => 'remove' );`
`1805`	`1805`	`}`
`1806`	`1806`
`1807`		`- $content = preg_replace( '/[\x00-\x08\x0B\x0C\x0E-\x1F]/', '', $content );`
	`1807`	`+ $content = preg_replace('/[\x00-\x08\x0B\x0C\x0E-\x1F]/', '', $content ?? '');`
`1808`	`1808`	`if ( 'remove' === $options['slash_zero'] ) {`
`1809`	`1809`	`$content = preg_replace( '/\\\\+0+/', '', $content );`
`1810`	`1810`	`}`