REDHAT-BUG-2503521: Medium severity Mozilla Firefox vulnerability
Published Jul 21, 2026
·Updated
Privilege escalation in WebExtensions. This vulnerability was fixed in Firefox 153 and Firefox ESR 140.13.
Affected Software
2 affected components
Mozilla Firefox<153
Mozilla Firefox ESR<140.13
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Firefoxto a version that resolves this vulnerability.Fixed in 153 - Upgrade
Upgrade
Firefox ESRto a version that resolves this vulnerability.Fixed in 140.13
Event History
Jul 21, 2026
Data Sourced
via Red Hat·01:05 PM
DescriptionSeverityAffected Software
Frequently Asked Questions
1
What is the severity of REDHAT-BUG-2503521?
The severity of REDHAT-BUG-2503521 is medium with a score of 4.
2
How do I fix REDHAT-BUG-2503521?
To fix REDHAT-BUG-2503521, update to Firefox version 153 or Firefox ESR version 140.13.
3
What types of software are affected by REDHAT-BUG-2503521?
REDHAT-BUG-2503521 affects Mozilla Firefox and Mozilla Firefox ESR.
4
What kind of vulnerability is REDHAT-BUG-2503521?
REDHAT-BUG-2503521 is a privilege escalation vulnerability in WebExtensions.
5
When was REDHAT-BUG-2503521 published?
REDHAT-BUG-2503521 was published on July 21, 2026.