CVE-2025-14333: Memory safety bugs fixed in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146

Published Dec 9, 2025
·
Updated

Memory safety bugs present in Firefox ESR 140.5, Thunderbird ESR 140.5, Firefox 145 and Thunderbird 145. 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.

Affected Software

12 affected componentsFixes available
Mozilla Firefox ESR<140.6
Mozilla Thunderbird ESR<140.6
Mozilla Firefox<146
Mozilla Thunderbird<146
Mozilla Firefox ESR<140.6
140.6
Mozilla Firefox<146
146
Mozilla Thunderbird<146
146
Mozilla Thunderbird<140.6
140.6
Mozilla Firefox<140.6.0
Mozilla Firefox<146.0
Mozilla Thunderbird<140.6.0
Mozilla Thunderbird<146.0

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 140.6
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 146
  3. Upgrade

    Upgrade Firefox to a version that resolves this vulnerability.

    Fixed in 146
  4. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 140.6
  5. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 146
  6. Upgrade

    Upgrade Thunderbird ESR to a version that resolves this vulnerability.

    Fixed in 140.6

Event History

Dec 9, 2025
CVE Published
via Mozilla·12:00 AM
Data Sourced
via Mozilla·12:00 AM
DescriptionSeverityAffected Software
Updated
via Mozilla·12:00 AM
Affected Software
CVE Published
via MITRE·01:38 PM
Data Sourced
via MITRE·01:38 PM
Description
Data Sourced
via Red Hat·02:01 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·04:17 PM
DescriptionSeverityWeaknessAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the severity of CVE-2025-14333?

CVE-2025-14333 has been identified with a high severity level due to potential exploitation for arbitrary code execution.

2

How do I fix CVE-2025-14333?

To fix CVE-2025-14333, update Mozilla Firefox and Thunderbird to versions 140.6 or later.

3

Which versions are affected by CVE-2025-14333?

CVE-2025-14333 affects Firefox ESR versions up to 140.5, Thunderbird ESR versions up to 140.5, and standard Firefox and Thunderbird versions up to 145.

4

What type of vulnerability is CVE-2025-14333?

CVE-2025-14333 is a memory safety bug that can lead to memory corruption.

5

Is there a known exploit for CVE-2025-14333?

While there are no confirmed exploits publicly available for CVE-2025-14333, the nature of the bug could allow for arbitrary code execution if successfully exploited.

Contact

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