CVE-2026-84129
Received Received - Intake

Firefox DOM Navigation Site Isolation Flaw

Publication date: 2026-09-01

Last updated on: 2026-09-01

Assigner: Mozilla Corporation

Description
Site isolation issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 155 and Firefox ESR 153.2.

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Meta Information

Published
2026-09-01
Last Modified
2026-09-01
Generated
2026-09-01
AI Q&A
2026-09-01
EPSS Evaluated
N/A
NVD
CVE-2026-84129
EUVD
EUVD-2026-69078

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
mozilla firefox to 155 (inc)
mozilla firefox_esr to 153.2 (inc)

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This is a site isolation issue in Firefox's DOM Navigation component. It allows potential data leakage between different websites due to improper separation of site contexts. The vulnerability was patched in Firefox 155 and Firefox ESR 153.2.

Impact Analysis

An attacker could exploit this to access sensitive data from one website while you are logged into another site. This could lead to theft of cookies, session tokens, or other private information across different browsing contexts.

Mitigation Strategies

Update Firefox to version 155 or later and Firefox ESR to version 153.2 or later to address the site isolation issue in the DOM Navigation component.

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