CVE 2017-5438
A use-after-free vulnerability during XSLT processing due to the result handler being held by a freed handler during handling. This results in 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.
