CVE-2018-5187: Canonical Ubuntu Linux

Critical severity, CVSS 9.8. EPSS: 3% chance of exploitation in the next 30 days.

Memory safety bugs present in Firefox 60 and Firefox ESR 60. 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 Thunderbird < 60, Firefox ESR < 60.1, and Firefox < 61.

Affected products

• Canonical Ubuntu Linux: version 14.04 only; version 16.04 only; version 17.10 only; version 18.04 only
• Debian Debian Linux: version 8.0 only; version 9.0 only
• Mozilla Firefox: before 60.1.0 (fixed in 60.1.0); before 61.0 (fixed in 61.0)
• Mozilla Thunderbird: before 60.0 (fixed in 60.0)

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