VULNERABILITY INTELLIGENCE

CVE-2025-6433

CVSS score9.8 CRITICAL
EPSS probability0.30%
CISA KEVNot currently listed
Published2025-06-24
Last modified2026-09-30
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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.

Weakness classification

  • 134c704f-9b21-4f2e-91b3-4a467353bcc0: CWE-295

Primary references