---
id: CVE-2020-12404
title: >-
  For native-to-JS bridging the app requires a unique token to be passed that
  ensures non-app code can't call the bridging functions
summary: >-
  For native-to-JS bridging the app requires a unique token to be passed that
  ensures non-app code can't call the bridging functions. That token could leak
  when used for downloading files. This vulnerability affects Firefox for iOS <
  26.
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N'
cwe:
  - CWE-79
vendor: mozilla
product: firefox_mobile
affected:
  - firefox_mobile < 26.0
patched:
  - firefox_mobile 26.0
published: '2020-07-09'
updated: '2026-08-19'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-12404'
references:
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=1631739'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2020-19/'
    label: security@mozilla.org
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=1631739'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.mozilla.org/security/advisories/mfsa2020-19/'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00784
epssPercentile: 0.54114
ingestedAt: '2026-08-19T15:41:14.205Z'
---

## Overview

For native-to-JS bridging the app requires a unique token to be passed that ensures non-app code can't call the bridging functions. That token could leak when used for downloading files. This vulnerability affects Firefox for iOS < 26.

## Affected

- `firefox_mobile < 26.0`

## Remediation

Upgrade past the affected range:

- `firefox_mobile 26.0`