REDHAT-BUG-2503434: Medium severity Mozilla Firefox vulnerability
Published Jul 21, 2026
·Updated
Same-origin policy bypass in the Networking: DNS component. This vulnerability was fixed in Firefox 153 and Firefox ESR 140.13.
Affected Software
2 affected components
Mozilla Firefox<153, =140.13
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·01:02 PM
DescriptionSeverityAffected Software
Frequently Asked Questions
1
What is the severity of REDHAT-BUG-2503434?
The severity of REDHAT-BUG-2503434 is medium, rated at 4.
2
How do I fix REDHAT-BUG-2503434?
You can fix REDHAT-BUG-2503434 by updating to Firefox version 153 or Firefox ESR version 140.13.
3
What impact does REDHAT-BUG-2503434 have?
REDHAT-BUG-2503434 allows for a same-origin policy bypass in the Networking: DNS component.
4
Which software is affected by REDHAT-BUG-2503434?
REDHAT-BUG-2503434 affects Mozilla Firefox and Mozilla Firefox ESR.
5
When was REDHAT-BUG-2503434 published?
REDHAT-BUG-2503434 was published on July 21, 2026.