Multiple unspecified vulnerabilities in the browser engine in Mozilla Firefox before 49.0, Firefox ESR 45.x before 45.4 and Thunderbird < 45.4 allow remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via unknown vectors.
Severity
CVSS 3.0
9.8 critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
4.2% chance of exploitation in the next 30 days; higher than 91% of CVEs (scores of 2026-10-31)