---
id: CVE-2026-16371
title: 'Privilege escalation in the DOM: Navigation component'
summary: >-
  Privilege escalation in the DOM: Navigation component. This vulnerability was
  fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, Thunderbird 140.13,
  Firefox ESR 140.15, and Thunderbird 140.15.
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'
cvssSource: adp
vendor: Mozilla
product: Firefox
affected:
  - Firefox
  - Thunderbird
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-07-24T03:55:30.041879Z'
published: '2026-07-21'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T13:49:31.123Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-16371'
references:
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=2008369'
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-68/'
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-70/'
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-71/'
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-72/'
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-84/'
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-87/'
tags:
  - cve.org
epss: 0.00297
epssPercentile: 0.21033
ingestedAt: '2026-10-21T13:57:01.110Z'
---

## Overview

Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, Thunderbird 140.13, Firefox ESR 140.15, and Thunderbird 140.15.

## Affected

- `Firefox`
- `Thunderbird`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.