CVE-2025-6433

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2025-6433
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.

9.8 /10

CVSS v3 : CRITICAL

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=1954033 Permissions Required
https://www.mozilla.org/security/advisories/mfsa2025-51/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-54/
Configurations

Configuration 1 (hide)

cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
History

13 Apr 2026, 15:17

Type Values Removed Values Added
Summary (en) 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 affects Firefox < 140 and Thunderbird < 140. (en) 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.

14 Jul 2025, 19:15

Type Values Removed Values Added
References
  • () https://www.mozilla.org/security/advisories/mfsa2025-54/ -
Summary (en) 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 affects Firefox < 140. (en) 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 affects Firefox < 140 and Thunderbird < 140.

03 Jul 2025, 16:04

Type Values Removed Values Added
References () https://bugzilla.mozilla.org/show_bug.cgi?id=1954033 - () https://bugzilla.mozilla.org/show_bug.cgi?id=1954033 - Permissions Required
References () https://www.mozilla.org/security/advisories/mfsa2025-51/ - () https://www.mozilla.org/security/advisories/mfsa2025-51/ - Vendor Advisory
CPE cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
First Time Mozilla firefox
Mozilla

25 Jun 2025, 13:15

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 9.8
Summary
  • (es) Si un usuario visitaba una página web con un certificado TLS no válido y concedía una excepción, la página web podía generar un desafío de WebAuthN que el usuario debía completar. Esto infringe la especificación de WebAuthN, que exige "un transporte seguro establecido sin errores". Esta vulnerabilidad afecta a Firefox anterior a la versión 140.
CWE CWE-295

24 Jun 2025, 13:15

Type Values Removed Values Added
New CVE
Information

Published : 2025-06-24 13:15

Updated : 2026-04-13 15:17

NVD link : CVE-2025-6433

Mitre link : CVE-2025-6433

CVE.ORG link : CVE-2025-6433

JSON object : View

Products Affected

mozilla

  • firefox
CWE
CWE-295

Improper Certificate Validation