CVE-2020-12396: Mozilla Firefox

Critical severity, CVSS 9.8. EPSS: 1.6% chance of exploitation in the next 30 days.

Mozilla developers and community members reported memory safety bugs present in Firefox 75. 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 < 76.

Affected products

• Mozilla Firefox: before 76.0 (fixed in 76.0)

Published 2020-05-26. Last modified 2026-06-17.