CVE-2025-13027: Mozilla Firefox

High severity, CVSS 8.1. EPSS: 0.3% chance of exploitation in the next 30 days.

Memory safety bugs present in Firefox 144 and Thunderbird 144. 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 was fixed in Firefox 145 and Thunderbird 145.

Affected products

• Mozilla Firefox: before 145.0 (fixed in 145.0)

Published 2025-11-11. Last modified 2026-06-17.