TeamCity is a mature CI/CD solution and we regularly make updates to improve the security of both TeamCity and the infrastructure for TeamCity Cloud.
How you configure and use TeamCity plays a vital role in the overall security of your TeamCity and TeamCity Cloud instance. We’ve published a blog which highlights many of the most important considerations and principles to account for when utilizing TeamCity.
Guest accounts are disabled by default in TeamCity Cloud, but can be optionally enabled by a TeamCity administrator.
If you have additional questions or concerns regarding privacy and security in TeamCity Cloud, please contact us.