An authentication bypass vulnerability exists in multiple WSO2 products when FIDO authentication is enabled. When a user account is deleted, the system does not automatically remove associated FIDO registration data. If a new user account is later created using the same username, the system may associate the new account with the previously registered FIDO device. This flaw may allow a previously deleted user to authenticate using their FIDO credentials and impersonate the newly created user, resulting in unauthorized access. The vulnerability applies only to deployments that utilize FIDO-based authentication.