Increasingly named as the number one non-traditional risk cyber-attacks against Cyber-manufacturing Systems (CMS) can cause a wide variety of losses. As the 4th industrial revolution is taking place CMS have become more resilient with the implementation of prevention, detection, redundancy, withstanding, and recovery mechanisms against cyber-attacks. However, the ever-evolving nature of these threats require systems to still be prepared for their eventual occurrence as it’s been demonstrated in the increasingly more common advent of successful cyber-attacks. While multiple generic threat models have been proposed by academics and government organizations for assessing the impact of cyber-attacks against Cyber-Physical Systems there is a research gap when it comes to manufacturing specific applications and how to assess their severity. In order to evaluate the impact of a cyber-attack against CMS this taxonomy proposes a classification of threats severity comprising three general themes: i) Operational Impact: Effective production time loss that incur in inability to yield the expected output, ii) Economic Impacts: Direct financial cost of the attack, mitigation, and recovery, and iii) Intangible Losses: Integrity breaches against original patents, models, or intangible actives.