CVE-2026-16388

Analyzed Analyzed - Analysis Complete

DOM Sandbox Escape in Firefox Networking

Publication date: 2026-07-21

Last updated on: 2026-07-24

Assigner: Mozilla Corporation

Description

Sandbox escape in the DOM: Networking component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-07-21

Last Modified

2026-07-24

Generated

2026-08-10

AI Q&A

2026-07-21

EPSS Evaluated

2026-08-09

NVD

CVE-2026-16388

EUVD

EUVD-2026-46225

Affected Vendors & Products

Vendor	Product	Version / Range
mozilla	thunderbird	to 153.0 (exc)
mozilla	firefox	to 153.0.0 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-693	The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product.

Attack-Flow Graph

Executive Summary

This is a sandbox escape vulnerability in Firefox's DOM Networking component. It allows malicious code to break out of the browser's security sandbox, potentially gaining access to system resources or other sensitive data.

Impact Analysis

If exploited, this vulnerability could allow an attacker to execute arbitrary code on your system, steal sensitive information, or perform actions outside the browser's intended security boundaries. Users of affected Firefox versions are at risk until they update.

Compliance Impact

This vulnerability allows sandbox escape in the DOM networking component, potentially enabling unauthorized access to sensitive data or system resources. Such a high-severity issue (CVSS 9.8) could violate compliance requirements under GDPR (e.g., unauthorized data access) or HIPAA (e.g., protected health information exposure) if exploited.

Mitigation Strategies

Update Firefox to version 153 or later to address the sandbox escape vulnerability in the DOM Networking component.

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