CVE-2024-9403: Mozilla Firefox

High severity, CVSS 7.3. EPSS: 0.4% chance of exploitation in the next 30 days.

Memory safety bugs present in Firefox 130. 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 and Thunderbird < 131.

Affected products

• Mozilla Firefox: before 131.0 (fixed in 131.0)
• Mozilla Thunderbird: before 131.0 (fixed in 131.0)

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