You can find SDL Tridion Sites hotfixes on the hotfixes page. This can also be found in the subnavigation for the Tridion Sites Developers Group.
As a general practice, it's a good idea to work with Support on any specific issues and to be sure to remain up-to-date on the latest version of your software, which often include any and all fixes that apply for that version.
For example, if using SDL Web 8, you can get all general fixes for that version and remain current with Support by using SDL Web 8.1.1.
Note that some hotfixes apply to specific issues and it's important to review the details of any fix before applying it to a given environment.
Find the product support policies for SDL Tridion Sites and other products on the SDL Support page.