REDHAT-BUG-2455897: High severity Mozilla Firefox vulnerability

Published Apr 7, 2026
·
Updated

Memory safety bugs present in Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 149.0.2 and Firefox ESR < 140.9.1.

Affected Software

4 affected components
Mozilla Firefox<149.0.2
Mozilla Firefox ESR<140.9.1
Mozilla Thunderbird=149.0.1
Mozilla Thunderbird ESR=140.9.0

Event History

Apr 7, 2026
Data Sourced
via Red Hat·01:01 PM
DescriptionSeverityAffected Software
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Frequently Asked Questions

1

What is the severity of REDHAT-BUG-2455897?

The severity of REDHAT-BUG-2455897 is high due to potential memory corruption issues that could lead to arbitrary code execution.

2

How do I fix REDHAT-BUG-2455897?

To fix REDHAT-BUG-2455897, update your Mozilla Firefox or Thunderbird to the latest patched versions as specified in the advisories.

3

Which versions are affected by REDHAT-BUG-2455897?

REDHAT-BUG-2455897 affects Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1, and Thunderbird 149.0.1.

4

Is there a known exploit for REDHAT-BUG-2455897?

There is no confirmed exploit publicly disclosed for REDHAT-BUG-2455897, but the vulnerability demonstrates potential for exploitation.

5

What are the potential risks of REDHAT-BUG-2455897?

The potential risks of REDHAT-BUG-2455897 include memory corruption that could be leveraged to execute arbitrary code on affected systems.

Contact

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