---
id: CVE-2025-55029
title: >-
  Malicious scripts could bypass the popup blocker to spam new tabs, potentially
  resulting in denial of service attacks
summary: >-
  Malicious scripts could bypass the popup blocker to spam new tabs, potentially
  resulting in denial of service attacks. This vulnerability was fixed in
  Firefox for iOS 142.
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-400
vendor: mozilla
product: firefox
affected:
  - firefox < 142.0
patched:
  - firefox 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-2025-55029'
references:
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=1973577'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2025-68/'
    label: security@mozilla.org
tags:
  - nvd
epss: 0.00337
epssPercentile: 0.24744
ingestedAt: '2026-09-30T18:17:24.454Z'
---

## Overview

Malicious scripts could bypass the popup blocker to spam new tabs, potentially resulting in denial of service attacks. This vulnerability was fixed in Firefox for iOS 142.

## Affected

- `firefox < 142.0`

## Remediation

Upgrade past the affected range:

- `firefox 142.0`