CVE-2024-9401: Mozilla Firefox

Critical severity, CVSS 9.8. EPSS: 0.7% chance of exploitation in the next 30 days.

Memory safety bugs present in Firefox 130, Firefox ESR 115.15, Firefox ESR 128.2, and Thunderbird 128.2. 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 < 131, Firefox ESR < 128.3, Firefox ESR < 115.16, Thunderbird < 128.3, and Thunderbird < 131.

Affected products

• Mozilla Firefox: before 115.16.0 (fixed in 115.16.0); before 131.0 (fixed in 131.0); from 116.0, before 128.3.0 (fixed in 128.3.0)
• Mozilla Thunderbird: before 128.3.0 (fixed in 128.3.0); from 129.0, before 131.0 (fixed in 131.0)

Published 2024-10-01. Last modified 2026-06-17.