CVE-2011-3866: Mozilla Firefox

Medium severity, CVSS 4.3. EPSS: 1.4% chance of exploitation in the next 30 days.

Mozilla Firefox before 7.0 and SeaMonkey before 2.4 do not properly restrict availability of motion data events, which makes it easier for remote attackers to read keystrokes by leveraging JavaScript code running in a background tab.

Affected products

• Mozilla Firefox: up to and including 7.0
• Mozilla Seamonkey: before 2.4 (fixed in 2.4)

Published 2011-09-29. Last modified 2026-06-16.