CVE•Published 2025-06-24•Modified 2026-04-13•1 article on news•6 live references•NVD data
CVE-2025-6433Mozilla · Firefox
Vulnerability data via NVD (ingested)
CVSS v3.1
9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS percentile
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Weaknesses (CWE)
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.
Timeline
Published 2025-06-24
Modified 2026-04-13
External references
Search for exposed instances
Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).
Shodan · vuln tag0 hosts
vuln:CVE-2025-6433Hosts Shodan has explicitly fingerprinted as vulnerable.
Shodan · product
product:"Mozilla Firefox"All exposed Mozilla Firefox instances — cross-reference with the CVE's affected-version range.
Shodan · banner/body mention
http.html:"Firefox"HTTP body or banner mentions "Firefox" — catches deploys Shodan didn't identify as a product.
More intel sources (5)
Shodan report
vuln:CVE-2025-6433Country / ASN / product breakdown for the vuln query.
Censys
vulnerabilities.cve_id: CVE-2025-6433Censys host search filtered to this CVE id.
grep.app
CVE-2025-6433Public source-code mentions — fast PoC discovery.
GitHub code
CVE-2025-6433GitHub code search for direct mentions.
Google dork
"CVE-2025-6433" exploit -site:nvd.nist.govWrite-ups and news, NVD excluded.