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 was fixed in 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

30 Sep 2026, 18:10

Type	Values Removed	Values Added
Summary	(es) Si un usuario guardó una respuesta desde la pestaña Red en DevTools mediante la opción Guardar como del menú contextual, es posible que el archivo no se haya guardado con la extensión `.download`. Esto podría haber provocado que el usuario ejecutara accidentalmente un archivo malicioso. Esta vulnerabilidad afecta a Firefox anterior a la versión 140.	(es) Si un usuario guardó una respuesta desde la pestaña Red en DevTools mediante la opción Guardar como del menú contextual, es posible que el archivo no se haya guardado con la extensión '.download'. Esto podría haber provocado que el usuario ejecutara accidentalmente un archivo malicioso. Esta vulnerabilidad afecta a Firefox anterior a la versión 140.

Information

Published : 2025-06-24 13:15

Updated : 2026-09-30 18:10

NVD link : CVE-2025-6435

Mitre link : CVE-2025-6435

CVE.ORG link : CVE-2025-6435

JSON object : View

Products Affected

mozilla

firefox
thunderbird

CWE

CWE-434

Unrestricted Upload of File with Dangerous Type

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