CVE-2025-6435

HIGH EPSS 29.4%
Published Jun 24, 20251y ago · Modified Jun 17, 20262w ago
8.1 CVSS 3.1
High
Find Similar
Published Jun 24, 2025 1y ago
Last Modified Jun 17, 2026 2w ago

Description

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 Details

Base Score
8.1
Exploitability
2.2
Impact
5.9
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
29.4% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-434 Unrestricted Upload of File with Dangerous Type Resource Mgmt

Affected Products 2

VendorProductVersionRange
mozillafirefox* <140.0
mozillathunderbird* <140.0

References 4

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

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.