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

https://github.com/jnbr/void-packages firefox-66_0_4
https://github.com/void-linux/void-packages/pull/11526

firefox: update to 66.0.4.


A patch file from https://github.com/void-linux/void-packages/pull/11526.patch is attached