CVE-2025-6433
firefox: WebAuthn would allow a user to sign a challenge on a webpage with an invalid TLS certificate
Severity
LowRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · June 24, 2025
Updated · June 30, 2026
Description
A flaw was found in Firefox. The Mozilla Foundation's Security Advisory describes the following issue: 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".
Statement
Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 3.4CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:N/A:N
CWE not specified