Input validation error in Mozilla Firefox and Firefox for Android - CVE-2026-0889
Published: January 13, 2026
Vulnerability identifier: #VU121221
CSH Severity: Low
CVSS v4: 2.1 [CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-0889
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to insufficient validation of user-supplied input in the DOM: Service Workers component. A remote attacker can perform a denial of service attack.
Affected software
Mozilla Firefox
Firefox for Android
Mozilla Thunderbird
Firefox for Android
Mozilla Thunderbird
How to mitigate CVE-2026-0889
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