In 2023 alone, 90% of the world's largest energy companies suffered cybersecurity breaches either directly or through third parties, with critical infrastructure becoming a primary target for state-sponsored hackers and cybercriminals. From traditional power grids and oil and gas pipelines to renewable energy installations and industrial control systems (ICS), modern energy infrastructure now relies heavily on interconnected digital technologies. While this digital transformation enhances operational efficiency, it also widens. This paper uses a systematic literature review to identify the most common cyber threat and Smart Grid vulnerability mentioned and researched in the literature from 2018 to 2025. This paper also aims to map the vulnerabilities that allow for cyber threats to occur, with the idea that if we know. When power grids go dark, water stops flowing, or communication networks crash, it's not just a technology failure — it's a community-wide crisis. Smart Meters: These devices are used to measure and record electricity consumption in real-time. Distribution Automation. Since our first report in November 2024, we have cataloged an additional 50 CVE vulnerabilities in solar-based Distributed Energy Resource (DER) systems. The energy sector's increasing reliance on digital systems has.