---
id: CVE-2026-8091
title: 'Incorrect boundary conditions in the Audio/Video: Playback component'
summary: >-
  Incorrect boundary conditions in the Audio/Video: Playback component. This
  vulnerability was fixed in Firefox 150, Thunderbird 150, Firefox ESR 140.10.1,
  Thunderbird 140.10.1, and Firefox ESR 115.35.2.
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-754
  - CWE-805
vendor: mozilla
product: firefox
affected:
  - firefox < 115.35.2
  - 'firefox >= 140.0, < 140.10.1'
  - 'thunderbird >= 140.0, < 140.10.1'
patched:
  - firefox 140.10.1
  - thunderbird 140.10.1
published: '2026-05-07'
updated: '2026-07-22'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-8091'
references:
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=2029301'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-30/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-33/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-36/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-39/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-42/'
    label: security@mozilla.org
  - 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-2026-8091'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2467699'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-8091.json
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
tags:
  - nvd
epss: 0.00469
epssPercentile: 0.3975
ingestedAt: '2026-07-22T13:03:40.829Z'
---

## Overview

Incorrect boundary conditions in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 150, Thunderbird 150, Firefox ESR 140.10.1, Thunderbird 140.10.1, and Firefox ESR 115.35.2.

## Affected

- `firefox < 115.35.2`
- `firefox >= 140.0, < 140.10.1`
- `thunderbird >= 140.0, < 140.10.1`

## Remediation

Upgrade past the affected range:

- `firefox 140.10.1`
- `thunderbird 140.10.1`