CVE-2019-11751: Mozilla Firefox

High severity, CVSS 8.8. EPSS: 1.1% chance of exploitation in the next 30 days.

Logging-related command line parameters are not properly sanitized when Firefox is launched by another program, such as when a user clicks on malicious links in a chat application. This can be used to write a log file to an arbitrary location such as the Windows 'Startup' folder. <br>*Note: this issue only affects Firefox on Windows operating systems.*. This vulnerability affects Firefox < 69 and Firefox ESR < 68.1.

Affected products

• Mozilla Firefox: before 69.0 (fixed in 69.0)
• Mozilla Firefox ESR: before 68.1.0 (fixed in 68.1.0)

Published 2019-09-27. Last modified 2026-06-17.