CVE-2016-9079: Mozilla Firefox, Firefox ESR, and Thunderbird Use-After-Free Vulnerability

High severity, CVSS 7.5. Actively exploited: in CISA KEV since 2023-06-22. EPSS: 87.5% chance of exploitation in the next 30 days.

A use-after-free vulnerability in SVG Animation has been discovered. An exploit built on this vulnerability has been discovered in the wild targeting Firefox and Tor Browser users on Windows. This vulnerability affects Firefox < 50.0.2, Firefox ESR < 45.5.1, and Thunderbird < 45.5.1.

Affected products

• Debian Debian Linux: version 9.0 only
• Mozilla Firefox: before 50.0.2 (fixed in 50.0.2); before 45.5.1 (fixed in 45.5.1)
• Mozilla Thunderbird: before 45.5.1 (fixed in 45.5.1)
• Red Hat Enterprise Linux: version 5.0 only; version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Desktop: version 5.0 only; version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server: version 5.0 only; version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server Aus: version 7.3 only; version 7.4 only
• Red Hat Enterprise Linux Server Eus: version 7.3 only; version 7.4 only; version 7.5 only
• Red Hat Enterprise Linux Workstation: version 5.0 only; version 6.0 only; version 7.0 only
• Torproject Tor: affected versions not specified

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