CVE-2014-1576: Mozilla Firefox

High severity, CVSS 7.5. EPSS: 5.1% chance of exploitation in the next 30 days.

Heap-based buffer overflow in the nsTransformedTextRun function in Mozilla Firefox before 33.0, Firefox ESR 31.x before 31.2, and Thunderbird 31.x before 31.2 allows remote attackers to execute arbitrary code via Cascading Style Sheets (CSS) token sequences that trigger changes to capitalization style.

Affected products

• Mozilla Firefox: version 31.0 only; version 31.1.0 only; up to and including 32.0; version 30.0 only
• Mozilla Thunderbird: version 31.0 only; version 31.1.0 only

Published 2014-10-15. Last modified 2026-06-17.