Describe CVE-2017-5440.
What is CVE-2017-5440?
A use-after-free vulnerability during XSLT processing due to a failure to propagate error conditions during matching while evaluating context, leading to objects being used when they no longer exist. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53..