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.
Severity
CVSS 3.1
8.8 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
1.9% chance of exploitation in the next 30 days; higher than 79% of CVEs (scores of 2026-10-31)