The pretty-link plugin before 1.6.8 for WordPress has PrliLinksController::list_links SQL injection via the group parameter.
https://wpvulndb.com/vulnerabilities/8249
https://wordpress.org/plugins/pretty-link/#developers
https://euvd.enisa.europa.eu/vulnerability/EUVD-2015-9297
http://cinu.pl/research/wp-plugins/mail_9ca443a3759e5c7fd889ae0e02e044e6.html