CVE-2022-40962: Mozilla Firefox

High severity, CVSS 8.8. EPSS: 1.4% chance of exploitation in the next 30 days.

Mozilla developers Nika Layzell, Timothy Nikkel, Sebastian Hengst, Andreas Pehrson, and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 104 and Firefox ESR 102.2. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 102.3, Thunderbird < 102.3, and Firefox < 105.

Affected products

• Mozilla Firefox: before 105.0 (fixed in 105.0)
• Mozilla Firefox ESR: before 102.3 (fixed in 102.3)
• Mozilla Thunderbird: before 102.3 (fixed in 102.3)

Published 2022-12-22. Last modified 2026-06-17.