Nvidia has released updates today (Jan 9 2018) dealing with the issues. So I would assume there are risks since they have created updates.
http://us.download.nvidia.com/Windows/390.65/390.65-win10-win8-win7-desktop-release-notes.pdf
Table 2.1 Security Updates for NVIDIA Software Vulnerabilities CVE ID NVIDIA Issue Number Description CVE-2017-5753 1975134 Computer systems with microprocessors utilizing speculative execution and branch prediction may allow unauthorized disclosure of information to an attacker with local user access via a side-channel analysis. For more information on this issue, see the NVIDIA GPU security updates for speculative side channel Security Bulletin posted on the NVIDIA Product Security page
And specifically mentions GeForce in the aforementioned post http://nvidia.custhelp.com/app/answers/detail/a_id/4611
Affected Products
Product | OS
GeForce, Quadro, NVS | Windows, Linux, FreeBSD, Solaris
Tesla | Windows, Linux