Critical severity · published Aug 19, 2025
CVE-2025-55031
Malicious pages could use Firefox for iOS to pass FIDO: links to the OS and trigger the hybrid passkey transport
9.8
CVSS
0.4%
EPSS
No
On KEV
Description
Malicious pages could use Firefox for iOS to pass FIDO: links to the OS and trigger the hybrid passkey transport. An attacker within Bluetooth range could have used this to trick the user into using their passkey to log the attacker's computer into the target account. This vulnerability was fixed in Firefox for iOS 142 and Focus for iOS 142.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 37% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
Firefox · Mozilla
before 142.0 · source: NVD
FF
Firefox Focus · Mozilla
before 142.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-55031
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-55031
Issue Tracking
https://bugzilla.mozilla.org/show_bug.cgi?id=1979499
Issue Tracking
https://bugzilla.mozilla.org/show_bug.cgi?id=1979804
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-68/
Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-69/
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