SuiteCRM is an open-source, enterprise-ready Customer Relationship Management (CRM) software application. Prior to 7.15.2 and 8.10.2, the /legacy/Api/V8/OAuth2 password-grant endpoint returns distinct error messages for an invalid username and an invalid password. An unauthenticated remote attacker can use those response differences to enumerate valid CRM usernames and target confirmed accounts with password spraying, credential stuffing, brute-force, or social-engineering attacks. This issue is fixed in versions 7.15.2 and 8.10.2.