---
id: CVE-2026-16398
title: Site isolation issue in the Graphics component
summary: >-
  Site isolation issue in the Graphics component. This vulnerability was fixed
  in Firefox 153 and Thunderbird 153.
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cvssSource: adp
vendor: Mozilla
product: Firefox
affected:
  - Firefox
  - Thunderbird
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-07-22T17:21:13.018823Z'
published: '2026-07-21'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T13:50:38.196Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-16398'
references:
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=2048345'
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-68/'
  - url: 'https://www.mozilla.org/security/advisories/mfsa2026-71/'
tags:
  - cve.org
epss: 0.00149
epssPercentile: 0.03711
ingestedAt: '2026-10-21T13:57:01.102Z'
---

## Overview

Site isolation issue in the Graphics component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.

## Affected

- `Firefox`
- `Thunderbird`

## Remediation

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