CVE-2026-118021
Received Received - Intake

XPCOM Use-After-Free Sandbox Escape in Firefox

Publication date: 2026-10-27

Last updated on: 2026-10-27

Assigner: Mozilla Corporation

Description
Sandbox escape due to use-after-free in the XPCOM component. This vulnerability was fixed in Firefox 159.

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Meta Information

Published
2026-10-27
Last Modified
2026-10-27
Generated
2026-10-27
AI Q&A
2026-10-27
EPSS Evaluated
N/A
NVD
CVE-2026-118021
EUVD
EUVD-2026-110919

Affected Vendors & Products

Currently, no data is known.

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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 sandbox escape vulnerability caused by a use-after-free issue in the XPCOM component of Firefox. A use-after-free occurs when a program continues to use a pointer after the memory it points to has been freed, potentially allowing an attacker to execute arbitrary code or escape the browser sandbox.

Impact Analysis

This vulnerability could allow an attacker to break out of the browser sandbox and execute malicious code on your system. This could lead to unauthorized access to sensitive data, installation of malware, or further compromise of your device.

Mitigation Strategies

Update Firefox to version 159 or later to address the use-after-free vulnerability in the XPCOM component.

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