The aim of this annual report is to present an updated assessment of the threat posed by non-state actors' use of chemical, biological, radiological, or nuclear (CBRN) materials to cause adverse effects on society. The content is based solely on open source information and includes a selection of incidents that occurred in 2020. The report has been produced by a research group at FOI (Swedish Defence Research Agency), within the framework of a grant from the Swedish Ministry of Defence. No known CBRN-related terrorist attack has occurred during 2020. However, there is still a widespread concern for this type of attack to occur and the consequences it may generate in the society. Expressions of threats, propaganda and instructions on CBRN-attacks are still being disseminated within violent extremist communities, with the purpose of spreading fear and inspiring sympathizers to take action. Propaganda and expression of threats during this year has largely been influenced by the ongoing pandemic of covid-19 and the effects and consequences it has generated.