CVE-2025-6433

9.8 CRITICAL
Published: June 24, 2025 Modified: April 13, 2026
View on NVD

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1954033
Source: security@mozilla.org
Permissions Required
https://www.mozilla.org/security/advisories/mfsa2025-51/
Source: security@mozilla.org
Vendor Advisory

3 reference(s) from NVD

Quick Stats

CVSS v3 Score
9.8 / 10.0
EPSS (Exploit Probability)
0.1%
20th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

mozilla