CVE-2009-4100: Yoono

High severity, CVSS 9.3. EPSS: 3.9% chance of exploitation in the next 30 days.

Yoono extension before 6.1.1 for Firefox performs certain operations with chrome privileges, which allows user-assisted remote attackers to execute arbitrary commands and perform cross-domain scripting attacks via DOM event handlers such as onload.

Affected products

• Yoono Yoono: up to and including 6.1.0; version 2.0.2.474 only; version 2.0.3.564 only; version 2.0.4.641 only; version 2.1.0.743 only; version 2.2.1.1038 only; …

Published 2009-11-29. Last modified 2026-06-16.