Hashed codes of JavaScript objects are shared between pages. This allows for pointer leaks because an object's address can be discovered through hash codes, and also allows for data leakage of an object's content using these hash codes. This vulnerability affects Thunderbird < 45.7, Firefox ESR < 45.7, and Firefox < 51.
http://rhn.redhat.com/errata/RHSA-2017-0190.html
http://rhn.redhat.com/errata/RHSA-2017-0238.html
https://bugzilla.mozilla.org/show_bug.cgi?id=1312001
https://bugzilla.mozilla.org/show_bug.cgi?id=1330769
https://security.gentoo.org/glsa/201702-13
https://security.gentoo.org/glsa/201702-22
https://www.debian.org/security/2017/dsa-3771
https://www.debian.org/security/2017/dsa-3832
https://www.mozilla.org/security/advisories/mfsa2017-01/
https://www.mozilla.org/security/advisories/mfsa2017-02/