CVE-2025-6435

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. This vulnerability affects Firefox < 140 and Thunderbird < 140.

CVSS v3 8.1 HIGH

8.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.2 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=1950056	Permissions Required
https://bugzilla.mozilla.org/show_bug.cgi?id=1961777	Permissions Required
https://www.mozilla.org/security/advisories/mfsa2025-51/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-54/	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:mozilla:firefox::::::::
	cpe:2.3:a:mozilla:thunderbird::::::::

History

13 Nov 2025, 17:03

Type	Values Removed	Values Added
First Time		Mozilla thunderbird
References	~~() https://www.mozilla.org/security/advisories/mfsa2025-54/ -~~	() https://www.mozilla.org/security/advisories/mfsa2025-54/ - Vendor Advisory
CPE	cpe:2.3:a:mozilla:firefox:::::-:::*	cpe:2.3:a:mozilla:firefox:::::::: cpe:2.3:a:mozilla:thunderbird::::::::

Information

Published : 2025-06-24 13:15

Updated : 2025-11-13 17:03

NVD link : CVE-2025-6435

Mitre link : CVE-2025-6435

CVE.ORG link : CVE-2025-6435

JSON object : View

Products Affected

mozilla

thunderbird
firefox

CWE

CWE-434

Unrestricted Upload of File with Dangerous Type

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