This is a list of vulnerabilities in the Opera browser. Note that the most recent added was in April of 2018. I am sure that there have been updates.
https://www.cvedetails.com/vulnerability-list/vendor_id-1961/product_id-15008/Opera-Opera-Browser.html
It is also of interest that Opera is based on Chromium, so vulnerabilities in Chromium may also be resident in Opera, but not checked for that residence.
Always be aware of what you sign up for, and what your agreement entails, as far as your security is concerned.