There are many things that can impact project outcomes, and project risks come in a wide variety of flavors. That said, there are a few common project risks that PMs need to be aware of. This includes internal and external risks such as:
1. Scope creep
2. Client dependency risks
3. Budget overruns
4. Tight deadlines
5. Technology risks
6. Market changes
7. Legal and regulatory risk
Source: https://www.teamwork.com/project-management-guide/project-risk/