Memory safety bugs were reported in Firefox 52, Firefox ESR 45.8, Firefox ESR 52, and Thunderbird 52. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.
https://www.mozilla.org/security/advisories/mfsa2017-13/
https://www.mozilla.org/security/advisories/mfsa2017-12/
https://www.mozilla.org/security/advisories/mfsa2017-11/
https://www.mozilla.org/security/advisories/mfsa2017-10/
https://www.debian.org/security/2017/dsa-3831
https://access.redhat.com/errata/RHSA-2017:1201
https://access.redhat.com/errata/RHSA-2017:1106
https://access.redhat.com/errata/RHSA-2017:1104