Protection mechanism failure in Mozilla Firefox and Firefox for Android - CVE-2026-0881
Published: January 13, 2026
Vulnerability identifier: #VU121219
CSH Severity: High
CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-0881
CWE-ID: CWE-693
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to compromise the affected system.
The vulnerability exists due to insufficient implementation of security measures in the Messaging System component. A remote attacker can bypass implemented sandbox restrictions and compromise the affected system.
Affected software
Mozilla Firefox
Firefox for Android
Mozilla Thunderbird
Firefox for Android
Mozilla Thunderbird
How to mitigate CVE-2026-0881
Install updates from vendor's website.
Mozilla Firefox - update to 147.0
Firefox for Android - update to 147.0
Mozilla Thunderbird - update to 147.0
Firefox for Android - update to 147.0
Mozilla Thunderbird - update to 147.0