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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.

PUBLISHED Reserved 2025-06-20 | Published 2025-06-24 | Updated 2026-04-13 | Assigner mozilla

Product status

140 (rpm)
unaffected

140 (rpm)
unaffected

Credits

Simon

References

bugzilla.mozilla.org/show_bug.cgi?id=1954033

www.mozilla.org/security/advisories/mfsa2025-51/

www.mozilla.org/security/advisories/mfsa2025-54/

cve.org (CVE-2025-6433)

nvd.nist.gov (CVE-2025-6433)

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