---
id: CVE-2026-96869
title: Information disclosure in the Networking component
summary: >-
  Information disclosure in the Networking component. This vulnerability was
  fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird
  153.4, Firefox 157, and Firefox ESR 140.17.
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N'
cwe:
  - CWE-200
  - CWE-201
vendor: mozilla
product: firefox
affected:
  - firefox < 140.17.0
  - 'firefox >= 141.0, < 153.4.0'
  - 'firefox >= 154.0.0, < 157.0.0'
  - thunderbird < 140.17.0
  - 'thunderbird >= 141.0, < 153.4.0'
  - 'thunderbird >= 154.0, < 157.0'
patched:
  - firefox 157.0.0
  - thunderbird 157.0
published: '2026-09-29'
updated: '2026-10-05'
sourceUpdated: '2026-10-05T13:52:00.003'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-96869'
references:
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=2041248'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-100/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-101/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-102/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-103/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-97/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-99/'
    label: security@mozilla.org
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-96869.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-96869'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2543144'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-96869'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-96869'
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-102/#CVE-2026-96869'
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-99/#CVE-2026-96869'
  - url: 'https://access.redhat.com/errata/RHSA-2026:85240'
  - url: 'https://access.redhat.com/errata/RHSA-2026:76764'
  - url: 'https://access.redhat.com/errata/RHSA-2026:80674'
  - url: 'https://access.redhat.com/errata/RHSA-2026:76850'
  - url: 'https://access.redhat.com/errata/RHSA-2026:85243'
  - url: 'https://access.redhat.com/errata/RHSA-2026:85242'
  - url: 'https://access.redhat.com/errata/RHSA-2026:85241'
  - url: 'https://access.redhat.com/errata/RHSA-2026:85244'
  - url: 'https://access.redhat.com/errata/RHSA-2026:76761'
  - url: 'https://access.redhat.com/errata/RHSA-2026:80694'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00243
epssPercentile: 0.15392
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-29T14:35:35.881077Z'
ingestedAt: '2026-09-29T13:34:31.682Z'
scores:
  nvd: 4.3
  vendor: 6.1
---

## Overview

Information disclosure in the Networking component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, and Firefox ESR 140.17.

## Affected

- `firefox < 140.17.0`
- `firefox >= 141.0, < 153.4.0`
- `firefox >= 154.0.0, < 157.0.0`
- `thunderbird < 140.17.0`
- `thunderbird >= 141.0, < 153.4.0`
- `thunderbird >= 154.0, < 157.0`

## Remediation

Upgrade past the affected range:

- `firefox 157.0.0`
- `thunderbird 157.0`

## Vendor advisories

- **RHSA-2026:85240** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-10-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:85240)
- **RHSA-2026:76764** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-10-06 · [advisory](https://access.redhat.com/errata/RHSA-2026:76764)
- **RHSA-2026:80674** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-10-12 · [advisory](https://access.redhat.com/errata/RHSA-2026:80674)
- **RHSA-2026:76850** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8) · released 2026-10-06 · [advisory](https://access.redhat.com/errata/RHSA-2026:76850)
- **RHSA-2026:85243** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) · released 2026-10-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:85243)
- **RHSA-2026:85242** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.2) · released 2026-10-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:85242)
- **RHSA-2026:85241** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.4) · released 2026-10-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:85241)
- **RHSA-2026:85244** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6) · released 2026-10-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:85244)
- **RHSA-2026:76761** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-10-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:76761)
- **RHSA-2026:80694** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-10-12 · [advisory](https://access.redhat.com/errata/RHSA-2026:80694)
- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8 · updated 2026-10-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-96869.json)
