Mozilla developers and community members reported memory safety bugs present in Firefox ESR 60.2. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Firefox ESR < 60.3 and Thunderbird < 60.3.
Severity
CVSS 3.0
8.8 high
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
2.3% chance of exploitation in the next 30 days; higher than 83% of CVEs (scores of 2026-10-31)