The plugin is vulnerable to Reflected Cross-Site Scripting due to insufficient escaping/sanitization and validation via the url parameter found in the ~/swagger-iframe.php file which allows attackers to inject arbitrary web scripts onto the page, in versions up to and including 1.0.0.
https://example.com/wp-content/plugins/embed-swagger/swagger-iframe.php?url=https://wpscan.com?a="-alert(`XSS`)-"