CVE-2026-0881

critical

Description

Sandbox escape in the Messaging System component. This vulnerability affects Firefox < 147 and Thunderbird < 147.

References

https://www.mozilla.org/security/advisories/mfsa2026-04/

https://www.mozilla.org/security/advisories/mfsa2026-01/

https://bugzilla.mozilla.org/show_bug.cgi?id=2005845

Details

Source: Mitre, NVD

Published: 2026-01-13

Updated: 2026-01-15

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

Severity: Critical

EPSS

EPSS: 0.00055