CVE-2019-17008: Mozilla Firefox

High severity, CVSS 8.8. EPSS: 1.9% chance of exploitation in the next 30 days.

When using nested workers, a use-after-free could occur during worker destruction. This resulted in a potentially exploitable crash. This vulnerability affects Thunderbird < 68.3, Firefox ESR < 68.3, and Firefox < 71.

Affected products

• Mozilla Firefox: before 71.0 (fixed in 71.0)
• Mozilla Firefox ESR: before 68.3 (fixed in 68.3)
• Mozilla Thunderbird: before 68.3 (fixed in 68.3)
• Opensuse Leap: version 15.1 only

Published 2020-01-08. Last modified 2026-06-17.