CVE-2017-5425: Mozilla Firefox

High severity, CVSS 7.5. EPSS: 2% chance of exploitation in the next 30 days.

The Gecko Media Plugin sandbox allows access to local files that match specific regular expressions. On OS OX, this matching allows access to some data in subdirectories of "/private/var" that could expose personal or temporary data. This has been updated to not allow access to "/private/var" and its subdirectories. Note: this issue only affects OS X. Other operating systems are not affected. This vulnerability affects Firefox < 52 and Thunderbird < 52.

Affected products

• Mozilla Firefox: before 52.0 (fixed in 52.0)
• Mozilla Thunderbird: before 52.0 (fixed in 52.0)

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