REDHAT-BUG-2517874: High severity Mozilla Firefox vulnerability

Q: Which Firefox releases contain the fix?

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

Published Aug 18, 2026

Updated

Privilege escalation in the DOM: Networking component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1.

Affected Software

4 affected components

Mozilla Firefox<154

Mozilla Firefox ESR 115.39<115.39

Mozilla Firefox ESR 140.14<140.14

Mozilla Firefox ESR 153.1<153.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

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

Event History

Aug 18, 2026

Data Sourced

via Red Hat·12:56 PM

DescriptionSeverityAffected Software

Frequently Asked Questions

Which Firefox releases contain the fix?