A firefox-esr security update has been released for Debian GNU/Linux 8 LTS to address multiple security issues.

DLA 2243-1: firefox-esr security update

Package : firefox-esr
Version : 68.9.0esr-1~deb8u2
CVE ID : CVE-2020-12399 CVE-2020-12405 CVE-2020-12406 CVE-2020-12410

Multiple security issues have been found in the Mozilla Firefox web
browser, which could potentially result in the execution of arbitrary
code or a timing attack on cryptographic keys.

For Debian 8 "Jessie", these problems have been fixed in version
68.9.0esr-1~deb8u2.

We recommend that you upgrade your firefox-esr packages.

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at:   https://wiki.debian.org/LTS