---
id: CVE-2025-2857
title: >-
  Following the recent Chrome sandbox escape (CVE-2025-2783), various Firefox
  developers identified a similar pattern in our IPC code
summary: >-
  Following the recent Chrome sandbox escape (CVE-2025-2783), various Firefox
  developers identified a similar pattern in our IPC code. A compromised child
  process could cause the parent process to return an unintentionally powerful
  handle,…
severity: critical
cvss: 10
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H'
cwe:
  - CWE-668
vendor: mozilla
product: firefox
affected:
  - firefox < 136.0.4
  - firefox < 115.21.1
  - 'firefox >= 128.1.0, < 128.8.1'
patched:
  - firefox 128.8.1
published: '2025-03-27'
updated: '2026-09-30'
sourceUpdated: '2026-09-30T19:10:01.007'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-2857'
references:
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=1956398'
    label: security@mozilla.org
  - url: 'https://issues.chromium.org/issues/405143032'
    label: security@mozilla.org
  - url: 'https://www.cve.org/CVERecord?id=CVE-2025-2783'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2025-19/'
    label: security@mozilla.org
tags:
  - nvd
epss: 0.01921
epssPercentile: 0.79149
ingestedAt: '2026-09-30T19:21:07.231Z'
---

## Overview

Following the recent Chrome sandbox escape (CVE-2025-2783), various Firefox developers identified a similar pattern in our IPC code. A compromised child process could cause the parent process to return an unintentionally powerful handle, leading to a sandbox escape. 
The original vulnerability was being exploited in the wild. 
*This only affects Firefox on Windows. Other operating systems are unaffected.*. This vulnerability was fixed in Firefox 136.0.4, Firefox ESR 128.8.1, and Firefox ESR 115.21.1.

## Affected

- `firefox < 136.0.4`
- `firefox < 115.21.1`
- `firefox >= 128.1.0, < 128.8.1`

## Remediation

Upgrade past the affected range:

- `firefox 128.8.1`