CVE-2017-5402: Mozilla: Use-after-free working with events in FontFace objects (MFSA 2017-06)

Severity: Critical

CVSS Score: 9.8

A use-after-free can occur when events are fired for a "FontFace" object after the object has been already been destroyed while working with fonts. This results in a potentially exploitable crash. This vulnerability affects Firefox < 52, Firefox ESR < 45.8, Thunderbird < 52, and Thunderbird < 45.8.