REDHAT-BUG-2517835: High severity Mozilla Firefox vulnerability

Published Aug 18, 2026

Updated

Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1.

Affected Software

2 affected components

Mozilla Firefox=154, =115.39, =140.14, =153.1

Firefox ESR=115.39, =140.14, =153.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade Firefox to a version that resolves this vulnerability.
Fixed in 154
Upgrade
Upgrade Firefox ESR to a version that resolves this vulnerability.
Fixed in 115.39
Upgrade
Upgrade Firefox ESR to a version that resolves this vulnerability.
Fixed in 140.14
Upgrade
Upgrade Firefox ESR to a version that resolves this vulnerability.
Fixed in 153.1

Event History

Aug 18, 2026

Data Sourced

via Red Hat·12:50 PM

DescriptionSeverityAffected Software

Frequently Asked Questions

Which Firefox releases contain the fix?

The issue was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1.

What component is involved in this vulnerability?

The vulnerability affects the Graphics: CanvasWebGL component and can lead to privilege escalation because of incorrect boundary conditions.