CVE-2018-12376: Canonical Ubuntu Linux

Critical severity, CVSS 9.8. EPSS: 3.1% chance of exploitation in the next 30 days.

Memory safety bugs present in Firefox 61 and Firefox ESR 60.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 62, Firefox ESR < 60.2, and Thunderbird < 60.2.1.

Affected products

• Canonical Ubuntu Linux: version 14.04 only; version 16.04 only; version 18.04 only
• 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.