CVE-2017-5454: Mozilla Firefox

High severity, CVSS 7.5. EPSS: 2.5% chance of exploitation in the next 30 days.

A mechanism to bypass file system access protections in the sandbox to use the file picker to access different files than those selected in the file picker through the use of relative paths. This allows for read only access to the local file system. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 52.1, and Firefox < 53.

Affected products

• Mozilla Firefox: before 53.0 (fixed in 53.0); before 52.1.0 (fixed in 52.1.0)
• Mozilla Thunderbird: before 52.1.0 (fixed in 52.1.0)
• Red Hat Enterprise Linux: version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Desktop: version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server: version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server Aus: version 7.3 only; version 7.4 only
• Red Hat Enterprise Linux Server Eus: version 7.3 only; version 7.4 only; version 7.5 only
• Red Hat Enterprise Linux Workstation: version 6.0 only; version 7.0 only

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