---
id: CVE-2025-3029
title: >-
  A crafted URL containing specific Unicode characters could have hidden the
  true origin of the page, resulting in a potential spoofing attack
summary: >-
  A crafted URL containing specific Unicode characters could have hidden the
  true origin of the page, resulting in a potential spoofing attack. This
  vulnerability was fixed in Firefox 137, Firefox ESR 128.9, Thunderbird 137,
  and Thunderbir…
severity: high
cvss: 7.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L'
cwe:
  - CWE-290
vendor: mozilla
product: firefox
affected:
  - firefox < 128.9.0
  - firefox < 137.0
  - thunderbird < 128.9.0
  - 'thunderbird >= 129.0, < 137.0'
patched:
  - firefox 137.0
  - thunderbird 137.0
published: '2025-04-01'
updated: '2026-09-30'
sourceUpdated: '2026-09-30T18:10:00.190'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-3029'
references:
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=1952213'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2025-20/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2025-22/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2025-23/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2025-24/'
    label: security@mozilla.org
  - url: 'https://lists.debian.org/debian-lts-announce/2025/04/msg00005.html'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00342
epssPercentile: 0.25287
ingestedAt: '2026-09-30T18:17:24.430Z'
---

## Overview

A crafted URL containing specific Unicode characters could have hidden the true origin of the page, resulting in a potential spoofing attack. This vulnerability was fixed in Firefox 137, Firefox ESR 128.9, Thunderbird 137, and Thunderbird 128.9.

## Affected

- `firefox < 128.9.0`
- `firefox < 137.0`
- `thunderbird < 128.9.0`
- `thunderbird >= 129.0, < 137.0`

## Remediation

Upgrade past the affected range:

- `firefox 137.0`
- `thunderbird 137.0`