Input validation error in Mozilla Firefox and Firefox for Android - CVE-2025-6435
Published: June 24, 2025
Vulnerability identifier: #VU111896
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2025-6435
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Mozilla
Affected software:
Mozilla Firefox
Firefox for Android
Mozilla Firefox
Firefox for Android
Detailed vulnerability description
The vulnerability allows a remote attacker to manipulate file a downloaded extension.
The vulnerability exists due to insufficient validation of user-supplied input. If a user saved a response from the Network tab in Devtools using the Save As context menu option, that file may not have been saved with the .download file extension. This could have led to the user inadvertently running a malicious executable.
How to mitigate CVE-2025-6435
Install updates from vendor's website.