Craft CMS 4.0.0 before 4.18.9 and 5.0.0 before 5.11.2 contains an unauthenticated SQL injection vulnerability in the element search endpoint because the attribute parameter is concatenated into the query unsanitized and emulated PDO prepares allow stacked statements. Remote attackers can read and write the database, setting the admin flag or overwriting password hashes in the users table to gain administrator access.