---
id: CVE-2025-3033
title: >-
  After selecting a malicious Windows `.url` shortcut from the local filesystem,
  an unexpected file could be uploaded
summary: >-
  After selecting a malicious Windows `.url` shortcut from the local filesystem,
  an unexpected file could be uploaded.  

  *This bug only affects Firefox on Windows. Other operating systems are
  unaffected.*. This vulnerability was fixed in F…
severity: high
cvss: 7.7
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-73
vendor: mozilla
product: firefox
affected:
  - firefox < 137.0
  - thunderbird < 137.0
patched:
  - firefox 137.0
  - thunderbird 137.0
published: '2025-04-01'
updated: '2026-09-30'
sourceUpdated: '2026-09-30T19:10:01.007'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-3033'
references:
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=1950056'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2025-20/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2025-23/'
    label: security@mozilla.org
tags:
  - nvd
epss: 0.00173
epssPercentile: 0.06025
ingestedAt: '2026-09-30T19:21:07.232Z'
---

## Overview

After selecting a malicious Windows `.url` shortcut from the local filesystem, an unexpected file could be uploaded.  
*This bug only affects Firefox on Windows. Other operating systems are unaffected.*. This vulnerability was fixed in Firefox 137 and Thunderbird 137.

## Affected

- `firefox < 137.0`
- `thunderbird < 137.0`

## Remediation

Upgrade past the affected range:

- `firefox 137.0`
- `thunderbird 137.0`