CVE-2017-7766: Mozilla Firefox

High severity, CVSS 7.8. EPSS: 0.4% chance of exploitation in the next 30 days.

An attack using manipulation of "updater.ini" contents, used by the Mozilla Windows Updater, and privilege escalation through the Mozilla Maintenance Service to allow for arbitrary file execution and deletion by the Maintenance Service, which has privileged access. Note: This attack requires local system access and only affects Windows. Other operating systems are not affected. This vulnerability affects Firefox ESR < 52.2 and Firefox < 54.

Affected products

• Mozilla Firefox: before 52.2.0 (fixed in 52.2.0); before 54.0 (fixed in 54.0)

Published 2018-06-11. Last modified 2026-06-17.