CVE-2016-1974: Mozilla Firefox

High severity, CVSS 8.8. EPSS: 3% chance of exploitation in the next 30 days.

The nsScannerString::AppendUnicodeTo function in Mozilla Firefox before 45.0 and Firefox ESR 38.x before 38.7 does not verify that memory allocation succeeds, which allows remote attackers to execute arbitrary code or cause a denial of service (out-of-bounds read) via crafted Unicode data in an HTML, XML, or SVG document.

Affected products

• Mozilla Firefox: up to and including 44.0.2; version 38.0 only; version 38.0.1 only; version 38.0.5 only; version 38.1.0 only; version 38.1.1 only; …
• Mozilla Thunderbird: up to and including 38.6.0
• Opensuse Leap: version 42.1 only
• Opensuse Opensuse: version 13.1 only; version 13.2 only
• Oracle Linux: version 5.0 only; version 6 only; version 7 only
• Suse Linux Enterprise: version 12.0 only

Published 2016-03-13. Last modified 2026-06-17.