Security Certifications - Ubuntu 18.04 LTS is Common Criteria EAL2 certified - https://www.commoncriteriaportal.org/products/

[vineetha]

Ubuntu 18.04.4 is Common Criteria EAL2 certified.
Certification report - https://www.commoncriteriaportal.org/files/epfiles/Certification%20Report%20-%20Canonical%20Ubuntu%20Server%2018.04%20LTS.pdf
Security Target - https://www.commoncriteriaportal.org/files/epfiles/ST%20-%20Canonical%20Ubuntu%20Server%2018.04%20LTS.pdf