On April 30th, a critical security vulnerability affecting cPanel & WHM login authentication was identified by the vendor. This issue impacts all currently supported versions of cPanel and may expose servers to unauthorized access if left unpatched.
Where possible we have patched, however a small subset of customers have configurations active that prevent us from patching. We have secured these servers; however, this will restrict your log in access to cPanel and WHM on unpatched VPS Servers. More information on how you can log in can be found in this knowledge article: https://www.bluehost.com/help/article/cpanel-centos6-vulnerability
For guidance on how to update your WHM version, please refer to the official documentation: https://docs.cpanel.net/whm/cpanel/upgrade-to-latest-version/
IMPORTANT NOTE: Customers running older / unsupported cPanel versions are strongly advised to upgrade to a supported build immediately.