---
id: CVE-2025-9184
title: >-
  Memory safety bugs present in Firefox ESR 140.1, Thunderbird ESR 140.1,
  Firefox 141 and Thunderbird 141
summary: >-
  Memory safety bugs present in Firefox ESR 140.1, Thunderbird ESR 140.1,
  Firefox 141 and Thunderbird 141. Some of these bugs showed evidence of memory
  corruption and we presume that with enough effort some of these could have
  been exploit…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-119
vendor: mozilla
product: firefox
affected:
  - firefox < 140.2.0
  - firefox < 142.0
  - thunderbird < 140.2.0
  - thunderbird < 142.0
patched:
  - firefox 142.0
  - thunderbird 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-2025-9184'
references:
  - url: >-
      https://bugzilla.mozilla.org/buglist.cgi?bug_id=1929482%2C1976376%2C1979163%2C1979955
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2025-64/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2025-67/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2025-70/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2025-72/'
    label: security@mozilla.org
tags:
  - nvd
epss: 0.0038
epssPercentile: 0.29559
ingestedAt: '2026-09-30T18:17:24.458Z'
---

## Overview

Memory safety bugs present in Firefox ESR 140.1, Thunderbird ESR 140.1, Firefox 141 and Thunderbird 141. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 142, Firefox ESR 140.2, Thunderbird 142, and Thunderbird 140.2.

## Affected

- `firefox < 140.2.0`
- `firefox < 142.0`
- `thunderbird < 140.2.0`
- `thunderbird < 142.0`

## Remediation

Upgrade past the affected range:

- `firefox 142.0`
- `thunderbird 142.0`