Attackers can exploit known vulnerabilities to infiltrate a device's firmware and the communication between firmware binaries in order to pass between them. To improve cybersecurity, organizations must identify and mitigate the risks of the firmware they use. An attack graph (AG) can be used to assess and visually display firmware's risks by organizing the identified vulnerabilities into attack paths composed of sequences of actions attackers may perform to compromise firmware images. In this paper, we utilize AGs for firmware risk assessment. We propose MIRAGE (Multi-binary Image Risk Assessment with Attack Graph Employment), a framework for identifying potential attack vectors and vulnerable interactions between firmware binaries; MIRAGE accomplishes this by generating AGs for firmware inter-binary communication. To evaluate the MIRAGE framework, we collected a dataset of 1,343 firmware images. We propose models for examining the risks of firmware binaries and attack paths, demonstrate their implementation on the dataset of firmware images, and list the riskiest binaries. We present a case study with a detailed description of an actual attack implementation on a selected firmware from the dataset. The use cases of the proposed framework include identifying risky external interactions, assessing supply chain risks, and analyzing security with digital twins.