🔐 CVE Alert

CVE-2025-6435

HIGH 8.1

Save as in Devtools could download files without sanitizing the extension

CVSS Score
8.1
EPSS Score
0.0%
EPSS Percentile
0th

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.

Vendor mozilla
Product firefox
Ecosystems
Industries
Technology
Published Jun 24, 2025
Last Updated Apr 13, 2026
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Affected Versions

Mozilla / Firefox
All versions affected
Mozilla / Thunderbird
All versions affected

References

NVD ↗ CVE.org ↗ EPSS Data ↗
bugzilla.mozilla.org: https://bugzilla.mozilla.org/show_bug.cgi?id=1950056 bugzilla.mozilla.org: https://bugzilla.mozilla.org/show_bug.cgi?id=1961777 mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-51/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2025-54/

Credits

Ameen Basha M K