---
id: CVE-2025-55031
title: >-
  Malicious pages could use Firefox for iOS to pass FIDO: links to the OS and
  trigger the hybrid passkey transport
summary: >-
  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 co…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-601
vendor: mozilla
product: firefox
affected:
  - firefox < 142.0
  - firefox_focus < 142.0
patched:
  - firefox 142.0
  - firefox_focus 142.0
published: '2025-08-19'
updated: '2026-09-30'
sourceUpdated: '2026-09-30T18:10:00.190'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-55031'
references:
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=1979499'
    label: security@mozilla.org
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=1979804'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2025-68/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2025-69/'
    label: security@mozilla.org
tags:
  - nvd
epss: 0.00414
epssPercentile: 0.33308
ingestedAt: '2026-09-30T18:17:24.454Z'
---

## Overview

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.

## Affected

- `firefox < 142.0`
- `firefox_focus < 142.0`

## Remediation

Upgrade past the affected range:

- `firefox 142.0`
- `firefox_focus 142.0`