Sandbox Escape in Firefox Graphics Component Before

Publication date: 2026-01-13

Last updated on: 2026-06-30

Assigner: Mozilla Corporation

Description

Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-01-13

Last Modified

2026-06-30

Generated

2026-07-06

AI Q&A

2026-01-14

EPSS Evaluated

2026-07-05

NVD

CVE-2026-0879

Affected Vendors & Products

Vendor	Product	Version / Range
mozilla	firefox	to 147 (exc)
mozilla	firefox_esr	to 115.32 (exc)
mozilla	firefox_esr	to 140.7 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-119	The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.

Attack-Flow Graph

Executive Summary

This vulnerability is a sandbox escape caused by incorrect boundary conditions in the Graphics component of Firefox. It affects versions of Firefox before 147, Firefox ESR before 115.32, and Firefox ESR before 140.7.

Impact Analysis

The vulnerability can lead to a sandbox escape, which means an attacker could potentially execute code outside the restricted environment, leading to full compromise of confidentiality, integrity, and availability of the affected system.

Mitigation Strategies

To mitigate this vulnerability, immediately update Firefox to version 147 or later, or Firefox ESR to version 115.32 or later, including ESR 140.7 or later. These versions include fixes that address the sandbox escape due to incorrect boundary conditions in the Graphics component.

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