What are the biggest risks to Ethereum?

Could you elaborate on the most significant risks confronting Ethereum? Could you provide an insight into the vulnerabilities that Ethereum faces? What are the primary challenges that might potentially endanger the stability of this cryptocurrency platform? Could you detail the security issues that might arise and impact Ethereum's integrity? Additionally, could you discuss any economic or technological factors that could pose a threat to Ethereum's future? How can these risks be mitigated, and what strategies could be employed to safeguard Ethereum's position in the crypto market?