---
id: CVE-2026-8975
title: >-
  Memory safety bugs present in Firefox ESR 115.35, Firefox ESR 140.10 and
  Firefox 150
summary: >-
  Memory safety bugs present in Firefox ESR 115.35, Firefox ESR 140.10 and
  Firefox 150. 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…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
cwe:
  - CWE-119
  - CWE-787
vendor: mozilla
product: firefox
affected:
  - firefox < 115.36.0
  - firefox < 151.0.0
  - 'firefox >= 140.0, < 140.11.0'
  - thunderbird < 140.11
  - thunderbird < 151.0.0
patched:
  - firefox 140.11.0
  - thunderbird 151.0.0
published: '2026-05-19'
updated: '2026-07-23'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-8975'
references:
  - url: >-
      https://bugzilla.mozilla.org/buglist.cgi?bug_id=1860195%2C2029325%2C2029429%2C2029910%2C2035915%2C2038678%2C2038669
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-46/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-47/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-48/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-50/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-51/'
    label: security@mozilla.org
  - url: 'https://access.redhat.com/errata/RHSA-2026:21378'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:21380'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:21381'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:21382'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:22325'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:22643'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:26174'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:26268'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:26269'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:26270'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:26491'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:26492'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:26493'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:26521'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:26536'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:26539'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:26551'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:26606'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:26629'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:26630'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:27715'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/security/cve/CVE-2026-8975'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2479840'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-8975.json
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
tags:
  - nvd
epss: 0.00429
epssPercentile: 0.36718
ingestedAt: '2026-07-23T20:19:19.316Z'
---

## Overview

Memory safety bugs present in Firefox ESR 115.35, Firefox ESR 140.10 and Firefox 150. 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 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

## Affected

- `firefox < 115.36.0`
- `firefox < 151.0.0`
- `firefox >= 140.0, < 140.11.0`
- `thunderbird < 140.11`
- `thunderbird < 151.0.0`

## Remediation

Upgrade past the affected range:

- `firefox 140.11.0`
- `thunderbird 151.0.0`