The echosign plugin before 1.2 for WordPress has XSS via the templates/add_templates.php id parameter.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-10985
Reference (s):
- https://0x62626262.wordpress.com/2016/04/21/echosign-plugin-for-wordpress-xss-vulnerability/
- https://wordpress.org/plugins/echosign/#developers
- https://wpvulndb.com/vulnerabilities/8465