CVE-2012-1939: Mozilla Firefox

High severity, CVSS 9.3. EPSS: 3.1% chance of exploitation in the next 30 days.

jsinfer.cpp in Mozilla Firefox ESR 10.x before 10.0.5 and Thunderbird ESR 10.x before 10.0.5 does not properly determine data types, which allows remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via crafted JavaScript code.

Affected products

• Mozilla Firefox: version 10.0 only; version 10.0.1 only; version 10.0.2 only; version 10.0.3 only; version 10.0.4 only
• Mozilla Thunderbird ESR: version 10.0 only; version 10.0.1 only; version 10.0.2 only; version 10.0.3 only; version 10.0.4 only

Published 2012-06-05. Last modified 2026-06-16.