Input validation error in Firefox for Android and Mozilla Firefox - CVE-2026-16378
Published: July 22, 2026
Vulnerability identifier: #VU139002
CSH Severity: Low
CVSS v4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-16378
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform unauthorized actions.
The vulnerability exists due to improper input handling in the DOM: Copy & Paste and Drag & Drop component when handling copy, paste, and drag-and-drop operations. A remote attacker can trigger crafted user interface interactions to perform unauthorized actions.
Affected software
Firefox for Android
Mozilla Firefox
Mozilla Thunderbird
Mozilla Firefox
Mozilla Thunderbird
How to mitigate CVE-2026-16378
Install security update from vendor's website.
Firefox for Android - update to 153.0
Mozilla Firefox - update to 153.0
Mozilla Thunderbird - update to 153.0
Mozilla Firefox - update to 153.0
Mozilla Thunderbird - update to 153.0