CVE-2026-100789

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Use-after-free in Firefox Graphics Canvas2D

Publication date: 2026-09-29

Last updated on: 2026-09-30

Assigner: Mozilla Corporation

Description

Use-after-free in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.

CVSS Scores

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Meta Information

Published

2026-09-29

Last Modified

2026-09-30

Generated

2026-10-19

AI Q&A

2026-09-29

EPSS Evaluated

2026-10-18

NVD

CVE-2026-100789

EUVD

EUVD-2026-88941

Affected Vendors & Products

Vendor	Product	Version / Range
mozilla	firefox	153.4
mozilla	firefox	157
mozilla	firefox	115.42
mozilla	firefox	140.17
mozilla	firefox	to 153.4 (inc)
mozilla	firefox	to 115.42 (inc)
mozilla	firefox	to 140.17 (inc)

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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.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 is a use-after-free vulnerability in Firefox's Graphics: Canvas2D component. Use-after-free occurs when a program continues to use memory after it has been freed, potentially leading to crashes or arbitrary code execution.

Detection Guidance

This vulnerability is specific to Firefox's Graphics: Canvas2D component and requires checking the installed version of Firefox. Use the following commands to detect affected versions: For Linux/macOS, run 'firefox --version' or 'about:support' in the browser. For Windows, check 'Help > About Firefox' in the application. Compare the version against the fixed releases: Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, or Firefox ESR 140.17.

Impact Analysis

An attacker could exploit this to crash your browser or run malicious code on your system. This could lead to data theft, installation of malware, or unauthorized system access if combined with other vulnerabilities.

Compliance Impact

This vulnerability does not directly specify impacts on compliance standards like GDPR or HIPAA. However, use-after-free vulnerabilities can lead to arbitrary code execution, which may result in unauthorized data access or manipulation, potentially violating confidentiality and integrity requirements under such regulations.

Mitigation Strategies

Update Firefox to version 157 or later, Firefox ESR 115.42 or later, Firefox ESR 140.17 or later, or Firefox ESR 153.4 or later to address the use-after-free vulnerability in Graphics: Canvas2D.

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