CVE-2025-6433

CRITICAL

9.8

Description

If a user visited a webpage with an invalid TLS certificate, and granted an exception, the webpage was able to provide a WebAuthn challenge that the user would be prompted to complete. This is in violation of the WebAuthN spec which requires "a secure transport established without errors". This vulnerability was fixed in Firefox 140 and Thunderbird 140.

CVE Details

CVSS v3.1 Score9.8

SeverityCRITICAL

CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack VectorNETWORK

ComplexityLOW

Privileges RequiredNONE

User InteractionNONE

Published6/24/2025

Last Modified4/13/2026

Sourcenvd

Honeypot Sightings0

Affected Products

mozilla:firefox

Weaknesses (CWE)

CWE-295

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1954033(security@mozilla.org)

https://www.mozilla.org/security/advisories/mfsa2025-51/(security@mozilla.org)

https://www.mozilla.org/security/advisories/mfsa2025-54/(security@mozilla.org)

IOC Correlations

No correlations recorded

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