REDHAT-BUG-2517845: Medium severity Mozilla Firefox vulnerability
Published Aug 18, 2026
·Updated
Site isolation issue in the WebExtensions component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1.
Affected Software
1 affected component
Mozilla Firefox<154, <140.14, <153.1
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Mozilla Firefox (WebExtensions)to a version that resolves this vulnerability.Fixed in 154 - Upgrade
Upgrade
Mozilla Firefox ESR (WebExtensions)to a version that resolves this vulnerability.Fixed in 140.14 - Upgrade
Upgrade
Mozilla Firefox ESR (WebExtensions)to a version that resolves this vulnerability.Fixed in 153.1
Event History
Aug 18, 2026
Data Sourced
via Red Hat·12:53 PM
DescriptionSeverityAffected Software
Frequently Asked Questions
1
Which Firefox releases contain the fix?
The issue was fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1.
2
What component is involved?
The vulnerability affects the WebExtensions component and involves a site isolation issue.