CVE-2017-7779: Debian Linux

Critical severity, CVSS 9.8. EPSS: 2.7% chance of exploitation in the next 30 days.

Memory safety bugs were reported in Firefox 54, Firefox ESR 52.2, and Thunderbird 52.2. 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 < 52.3, Firefox ESR < 52.3, and Firefox < 55.

Affected products

• Debian Debian Linux: version 8.0 only; version 9.0 only
• Mozilla Firefox: before 55.0 (fixed in 55.0); before 52.3.0 (fixed in 52.3.0)
• Mozilla Thunderbird: before 52.3.0 (fixed in 52.3.0)
• 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 7.4 only
• Red Hat Enterprise Linux Server Eus: version 7.4 only; version 7.5 only
• Red Hat Enterprise Linux Workstation: version 6.0 only; version 7.0 only

Published 2018-06-11. Last modified 2026-06-17.