CVE-2026-100816
Received Received - Intake

Firefox Site Isolation DOM Networking Component Bypass

Publication date: 2026-09-29

Last updated on: 2026-09-29

Assigner: Mozilla Corporation

Description
Site isolation issue in the DOM: Networking component. This vulnerability was fixed in Firefox ESR 153.4 and Firefox 157.

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Meta Information

Published
2026-09-29
Last Modified
2026-09-29
Generated
2026-09-29
AI Q&A
2026-09-29
EPSS Evaluated
N/A
NVD
CVE-2026-100816
EUVD
EUVD-2026-88795

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
mozilla firefox to 153.4 (inc)
mozilla firefox to 157 (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 and Networking components. It allows potential data leakage between different websites due to improper separation of site contexts. The vulnerability was patched in Firefox ESR 153.4 and Firefox 157.

Impact Analysis

An attacker could exploit this to access sensitive data from one website while you are logged into another. This might include cookies, session tokens, or other private information, potentially leading to account hijacking or data theft.

Compliance Impact

This vulnerability could lead to unauthorized data exposure, violating GDPR's data protection principles or HIPAA's confidentiality requirements. Organizations using affected Firefox versions may face compliance violations and potential fines if user data is compromised.

Mitigation Strategies

Update Firefox ESR to version 153.4 or Firefox to version 157 or later to address the site isolation issue in the DOM: Networking component.

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