CVE-2026-16351

Analyzed Analyzed - Analysis Complete

DOM Navigation Use-After-Free in Firefox

Publication date: 2026-07-21

Last updated on: 2026-07-24

Assigner: Mozilla Corporation

Description

Sandbox escape due to use-after-free in the DOM: Navigation component. This vulnerability was fixed in Firefox 153, Firefox ESR 115.38, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.

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-2026-16351

EUVD

EUVD-2026-46192

Affected Vendors & Products

Vendor	Product	Version / Range
mozilla	firefox	to 153.0.0 (exc)
mozilla	firefox	to 115.38.0 (exc)
mozilla	firefox	From 128.1.0 (inc) to 140.13.0 (exc)
mozilla	thunderbird	to 140.13.0 (exc)
mozilla	thunderbird	From 141.0 (inc) to 153.0 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-416	The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Attack-Flow Graph

Executive Summary

This vulnerability is a sandbox escape caused by a use-after-free bug in the DOM Navigation component of Firefox. A use-after-free occurs when a program continues to use memory after it has been freed, potentially allowing attackers to execute arbitrary code or gain elevated privileges.

Detection Guidance

Detection requires checking Firefox version. Run 'firefox --version' or check 'about:support' in Firefox. If version is below 153 (standard) or 115.38/140.13 (ESR), the system is vulnerable.

Impact Analysis

This vulnerability could allow an attacker to escape the browser sandbox and execute malicious code on your system. If exploited, it may lead to unauthorized access, data theft, or installation of malware. Users of affected Firefox versions are at risk until they update to the patched versions.

Compliance Impact

This vulnerability is a sandbox escape due to use-after-free in the DOM Navigation component, which could allow malicious code to bypass security boundaries. Such exploits may lead to unauthorized data access or execution, potentially violating data protection requirements under GDPR or HIPAA if sensitive information is compromised.

Mitigation Strategies

Update Firefox to version 153 or later, Firefox ESR 115.38 or later, or Firefox ESR 140.13 or later. Disable automatic updates temporarily if needed until patches are applied.

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