Vulnerability in Mozilla Firefox
CVE-2026-4687
Sandbox escape due to incorrect boundary conditions in the Telemetry component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
EPSS: 0.000 (9.0th percentile) — read the EPSS interpretation.
Affected products
- Mozilla Firefox — versions 115.34, 140.9, 149
- Mozilla Thunderbird — versions 140.9, 149