CVE 2017-5464
During DOM manipulations of the accessibility tree through script, the DOM tree can become out of sync with the accessibility tree, leading to memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.
See the 
CVE page on Mitre.org
for more details.
