CVE-2024-8387: Mozilla Firefox

Critical severity, CVSS 9.8. EPSS: 0.6% chance of exploitation in the next 30 days.

Memory safety bugs present in Firefox 129, Firefox ESR 128.1, and Thunderbird 128.1. 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 < 130, Firefox ESR < 128.2, and Thunderbird < 128.2.

Affected products

• Mozilla Firefox: version 129.0 only
• Mozilla Firefox ESR: version 128.1 only
• Mozilla Thunderbird: version 128.1 only

Published 2024-09-03. Last modified 2026-06-17.