The Paid Memberships Pro WordPress Plugin, version < 2.9.8, is affected by an unauthenticated SQL injection vulnerability in the 'code' parameter of the '/pmpro/v1/order' REST route.
https://www.tenable.com/security/research/tra-2023-2
http://packetstormsecurity.com/files/171661/WordPress-Paid-Memberships-Pro-2.9.8-SQL-Injection.html