There is a new pull request by sgn against master on the void-packages repository

https://github.com/sgn/void-packages firefox-esr-update
https://github.com/void-linux/void-packages/pull/18140

Firefox esr update 68.4.1 for CVE
https://www.mozilla.org/en-US/firefox/68.4.1/releasenotes/

A patch file from https://github.com/void-linux/void-packages/pull/18140.patch is attached