CVE-2017-7828: Mozilla: Use-after-free of PressShell while restyling layout (MFSA 2017-25)

Severity: Critical

CVSS Score: 9.8

A use-after-free vulnerability can occur when flushing and resizing layout because the "PressShell" object has been freed while still in use. This results in a potentially exploitable crash during these operations. This vulnerability affects Firefox < 57, Firefox ESR < 52.5, and Thunderbird < 52.5.