system
Describe <CVE-2017-5440>.
user
What is <CVE-2017-5440>?
assistant
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..