CVE-2017-5403: When adding a range to an object in the DOM, it is possible to use "addRange" to add the range to an incorrect root object. This triggers a use-after-free, resulting in a potentially exploitable crash.

Severity: Critical

CVSS Score: 9.8

When adding a range to an object in the DOM, it is possible to use "addRange" to add the range to an incorrect root object. This triggers a use-after-free, resulting in a potentially exploitable crash. This vulnerability affects Firefox < 52 and Thunderbird < 52.