CVE-2026-2776

critical

Description

Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

References

https://www.mozilla.org/security/advisories/mfsa2026-17/

https://www.mozilla.org/security/advisories/mfsa2026-16/

https://www.mozilla.org/security/advisories/mfsa2026-15/

https://www.mozilla.org/security/advisories/mfsa2026-14/

https://www.mozilla.org/security/advisories/mfsa2026-13/

https://bugzilla.mozilla.org/show_bug.cgi?id=2015266

Details

Source: Mitre, NVD

Published: 2026-02-24

Updated: 2026-04-13

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 10

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H