One disturbing thing about Mozilla security is that most of the "Critical" flaws[1] in their list would be marked as "High" on Chrome because of Chrome's superior security model.
Oh sure, they are not magic smoke indeed. Still, how do you explain that Use after free bugs are marked Critical in Firefox but High on Chrome? Seems like Chrome is doing a little bit better in security department.
Security flaws browser vendors use do not have different classification schemes. They all use CVSS Severity scores, go ahead and check.
Also definitions:
Firefox
Critical: Vulnerability can be used to run attacker code and install software, requiring no user interaction beyond normal browsing.
High: Vulnerability can be used to gather sensitive data from sites in other windows or inject data or code into those sites, requiring no more than normal browsing actions
Chrome
Critical:Allows an attacker run arbitrary code with the user's privileges in the normal course of browsing.
High: Allows an attacker to read or modify confidential data belonging to other web sites.
[1]https://www.mozilla.org/security/known-vulnerabilities/firef...