A vulnerability in register allocation in JavaScript can lead to type confusion, allowing for an arbitrary read and write. This leads to remote code execution inside the sandboxed content process when triggered. This vulnerability affects Firefox ESR < 60.2.2 and Firefox < 62.0.3.
https://www.mozilla.org/security/advisories/mfsa2018-24/
https://www.debian.org/security/2018/dsa-4310
https://usn.ubuntu.com/3778-1/
https://security.gentoo.org/glsa/201810-01
https://bugzilla.mozilla.org/show_bug.cgi?id=1493900
https://access.redhat.com/errata/RHSA-2018:2884
https://access.redhat.com/errata/RHSA-2018:2881