CVE-2026-4686: Incorrect boundary conditions in the Graphics: Canvas2D component

Published Mar 24, 2026
·
Updated

Incorrect boundary conditions in the Graphics: Canvas2D component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9.

Other sources

Incorrect boundary conditions in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

MITRE

Affected Software

10 affected componentsFixes available
Mozilla Firefox<149
Mozilla Firefox ESR<115.34, <140.9
Mozilla Firefox<149
149
Mozilla Firefox ESR<115.34
115.34
Mozilla Firefox ESR<140.9
140.9
Mozilla Firefox<115.34.0
Mozilla Firefox<149.0
Mozilla Firefox>=128.0<140.9.0
Mozilla Thunderbird<140.9
140.9
Mozilla Thunderbird<149
149

Event History

Mar 24, 2026
CVE Published
via Mozilla·12:00 AM
Data Sourced
via Mozilla·12:00 AM
DescriptionSeverityAffected Software
Updated
via Mozilla·12:00 AM
Affected Software
CVE Published
via MITRE·12:30 PM
Data Sourced
via MITRE·12:30 PM
Description
Data Sourced
via Red Hat·01:03 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·01:16 PM
DescriptionSeverityWeaknessAffected Software
Apr 7, 58249
Event
via FIRST·11:15 AM

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the severity of CVE-2026-4686?

CVE-2026-4686 is classified as a critical vulnerability due to incorrect boundary conditions in the Graphics: Canvas2D component.

2

How do I fix CVE-2026-4686?

The fix for CVE-2026-4686 is to upgrade to Firefox version 149, Firefox ESR version 115.34, or Thunderbird version 149.

3

Which software versions are affected by CVE-2026-4686?

CVE-2026-4686 affects Firefox versions prior to 149, Firefox ESR versions prior to 115.34 and 140.9, and Thunderbird versions prior to 149 and 140.9.

4

What components are impacted by CVE-2026-4686?

CVE-2026-4686 specifically impacts the Graphics: Canvas2D component within the affected software.

5

Is there a workaround for CVE-2026-4686?

There are no recommended workarounds for CVE-2026-4686; users should update to the latest version of the affected software.

Contact

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