CVE-2020-6797: Mozilla Firefox

Medium severity, CVSS 4.3. EPSS: 1.5% chance of exploitation in the next 30 days.

By downloading a file with the .fileloc extension, a semi-privileged extension could launch an arbitrary application on the user's computer. The attacker is restricted as they are unable to download non-quarantined files or supply command line arguments to the application, limiting the impact. Note: this issue only occurs on Mac OSX. Other operating systems are unaffected. This vulnerability affects Thunderbird < 68.5, Firefox < 73, and Firefox < ESR68.5.

Affected products

• Mozilla Firefox: before 73.0 (fixed in 73.0)
• Mozilla Firefox ESR: before 68.5.0 (fixed in 68.5.0)
• Mozilla Thunderbird: before 68.5.0 (fixed in 68.5.0)

Published 2020-03-02. Last modified 2026-06-17.