There hasn't been a GLSA (Gentoo Linux Security Advisory) for Firefox since 2007. Why? https://security.gentoo.org/glsa @GentooHardened
Good catch! But still no GLSA for fixes in https://www.mozilla.org/en-US/security/known-vulnerabilities/firefox-esr/#firefoxesr45.2 … https://www.mozilla.org/en-US/security/known-vulnerabilities/firefox-esr/#firefoxesr45.3 … https://www.mozilla.org/en-US/security/known-vulnerabilities/firefox-esr/#firefoxesr45.4 … Firefox 38.8 is EOL!