CVE-2018-12379: Debian Linux

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

When the Mozilla Updater opens a MAR format file which contains a very long item filename, an out-of-bounds write can be triggered, leading to a potentially exploitable crash. This requires running the Mozilla Updater manually on the local system with the malicious MAR file in order to occur. This vulnerability affects Firefox < 62, Firefox ESR < 60.2, and Thunderbird < 60.2.1.

Affected products

• Debian Debian Linux: version 8.0 only; version 9.0 only
• Mozilla Firefox: before 60.2.0 (fixed in 60.2.0); before 62.0 (fixed in 62.0)
• Mozilla Thunderbird: before 60.2.1 (fixed in 60.2.1)
• 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 7.6 only
• Red Hat Enterprise Linux Server Eus: version 7.5 only; version 7.6 only
• Red Hat Enterprise Linux Server Tus: version 7.6 only
• Red Hat Enterprise Linux Workstation: version 6.0 only; version 7.0 only

Published 2018-10-18. Last modified 2026-06-17.