---
id: CVE-2023-29540
title: >-
  Using a redirect embedded into <code>sourceMappingUrls</code> could allow for
  navigation to external protocol links in sandboxed iframes without
  <code>allow-top-navigation-to-custom-protocols</code>
summary: >-
  Using a redirect embedded into <code>sourceMappingUrls</code> could allow for
  navigation to external protocol links in sandboxed iframes without
  <code>allow-top-navigation-to-custom-protocols</code>. This vulnerability
  affects Firefox fo…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'
cwe:
  - CWE-601
vendor: mozilla
product: firefox
affected:
  - firefox < 112.0
  - firefox_mobile < 112.0
  - focus < 112.0
patched:
  - firefox 112.0
  - firefox_mobile 112.0
  - focus 112.0
published: '2023-06-02'
updated: '2026-08-19'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2023-29540'
references:
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=1790542'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2023-13/'
    label: security@mozilla.org
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=1790542'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.mozilla.org/security/advisories/mfsa2023-13/'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00315
epssPercentile: 0.21744
ingestedAt: '2026-08-19T15:41:15.618Z'
---

## Overview

Using a redirect embedded into <code>sourceMappingUrls</code> could allow for navigation to external protocol links in sandboxed iframes without <code>allow-top-navigation-to-custom-protocols</code>. This vulnerability affects Firefox for Android < 112, Firefox < 112, and Focus for Android < 112.

## Affected

- `firefox < 112.0`
- `firefox_mobile < 112.0`
- `focus < 112.0`

## Remediation

Upgrade past the affected range:

- `firefox 112.0`
- `firefox_mobile 112.0`
- `focus 112.0`