SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2025-55031

Malicious pages could use Firefox for iOS to pass FIDO: links to the OS and trigger the hybrid passkey transport.

CRITICAL 9.8EPSS 0.41%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.41%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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 3.1
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
0.41% probability · 35th percentile
CISA KEV
Not listed
Weakness
CWE-601
Affected
mozilla/firefox · mozilla/firefox focus
Source
security@mozilla.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.