With the increase in using computer networking, the security risk has also increased. To protect the network from attacks, attack graph has been used to analyze the vulnerabilies of the network. However, properly securing networks requires quantifying the level of security offered by these actions, as you cannot enhance what you cannot measure. Security metrics provide a qualitative and quantitative representation of a system's or network's security level. However, using existing security metrics can lead to misleading results. This work proposed three metrics, which is the Number of Vulnerabilities (NV), Mean Vulnerabilities on Path (MVoP), and the Weakest Path (WP). The experiment of this work used two networks to test the metrics. The results show the effect of these metrics on finding the weaknesses of the network that the attacker may use.