The SMS Alert WordPress plugin before 4.0.1 does not check that the acting administrator is allowed to manage the selected users before returning their stored billing phone numbers, allowing an administrator of one site on a multisite network to disclose the phone numbers of users who belong to other sites on that network. This affects multisite only, and requires the SMS Alert WordPress plugin before 4.0.1's gateway credentials to be stored on the acting administrator's own site.

The SMS Alert WordPress plugin before 4.0.1 does not check that the acting administrator is allowed to manage the selected users before returning their stored billing phone numbers, allowing an administrator of one site on a multisite network to disclose the phone numbers of users who belong to other sites on that network. This affects multisite only, and requires the SMS Alert WordPress plugin before 4.0.1's gateway credentials to be stored on the acting administrator's own site.