CVE-2019-11764: Canonical Ubuntu Linux

High severity, CVSS 8.8. EPSS: 1.5% chance of exploitation in the next 30 days.

Mozilla developers and community members reported memory safety bugs present in Firefox 69 and Firefox ESR 68.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.

Affected products

• Canonical Ubuntu Linux: version 16.04 only
• Mozilla Firefox: before 70.0 (fixed in 70.0)
• Mozilla Firefox ESR: before 68.2 (fixed in 68.2)
• Mozilla Thunderbird: before 68.2 (fixed in 68.2)

Published 2020-01-08. Last modified 2026-06-17.