REDHAT-BUG-2403774: High severity Mozilla Firefox vulnerability

Published Oct 14, 2025
·
Updated

Memory safety bugs present in Firefox ESR 140.3, Thunderbird ESR 140.3, Firefox 143 and Thunderbird 143. 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 < 144, Firefox ESR < 140.4, Thunderbird < 144, and Thunderbird < 140.4.

Affected Software

4 affected components
Mozilla Firefox<144
Mozilla Firefox ESR<140.4
Mozilla Thunderbird<144
Mozilla Thunderbird ESR<140.4

Event History

Oct 14, 2025
Data Sourced
via Red Hat·01:02 PM
DescriptionSeverityAffected Software
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Frequently Asked Questions

1

What is the severity of REDHAT-BUG-2403774?

REDHAT-BUG-2403774 includes memory safety bugs that could potentially lead to the execution of arbitrary code.

2

How do I fix REDHAT-BUG-2403774?

To fix REDHAT-BUG-2403774, upgrade to the latest version of Firefox ESR or Thunderbird ESR beyond the affected versions.

3

Which versions are affected by REDHAT-BUG-2403774?

REDHAT-BUG-2403774 affects Firefox and Thunderbird versions up to 144 and Firefox ESR and Thunderbird ESR versions up to 140.4.

4

Can REDHAT-BUG-2403774 be exploited remotely?

Yes, with sufficient effort, the memory safety issues in REDHAT-BUG-2403774 could be exploited to run arbitrary code remotely.

5

Are there any workarounds for REDHAT-BUG-2403774?

Temporary workarounds for REDHAT-BUG-2403774 involve using alternative email clients or browsers until the software is updated.

Contact

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