CVE-2026-12328: Memory safety bugs fixed in Firefox ESR 115.37, Firefox ESR 140.12, Thunderbird ESR 140.12, Firefox 152 and Thunderbird 152

Published Jun 16, 2026
·
Updated

Memory safety bugs present in Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird ESR 140.11, Firefox 151 and Thunderbird 151. 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

10 affected componentsFixes available
Mozilla Firefox ESR<140.12
140.12
Mozilla Firefox<152
152
Mozilla Firefox ESR<115.37
115.37
Mozilla Thunderbird<140.12
140.12
Mozilla Thunderbird<152
152
Mozilla Firefox<115.37.0
Mozilla Firefox<152.0
Mozilla Firefox>=140.0<140.12.0
Mozilla Thunderbird<152.0.0
Mozilla Thunderbird>=140.0<140.12.0

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 140.12
  2. Upgrade

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

    Fixed in 152
  3. Upgrade

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

    Fixed in 115.37
  4. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 115.37
  5. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 140.12
  6. Upgrade

    Upgrade Firefox to a version that resolves this vulnerability.

    Fixed in 152
  7. Upgrade

    Upgrade Thunderbird ESR to a version that resolves this vulnerability.

    Fixed in 140.12
  8. Upgrade

    Upgrade Thunderbird ESR to a version that resolves this vulnerability.

    Fixed in 115.37
  9. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 152

Event History

Jun 16, 2026
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·11:53 AM
Data Sourced
via MITRE·11:53 AM
Description
Data Sourced
via NVD·01:16 PM
DescriptionSeverityWeaknessAffected Software
Data Sourced
via Red Hat·02:01 PM
DescriptionSeverityAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

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Frequently Asked Questions

1

What is the severity of CVE-2026-12328?

The severity of CVE-2026-12328 is high, with a CVSS score of 8.1.

2

How do I fix CVE-2026-12328?

To fix CVE-2026-12328, update to Firefox ESR 115.37, Firefox ESR 140.12, Thunderbird ESR 140.12, Firefox 152, or Thunderbird 152.

3

What types of applications are affected by CVE-2026-12328?

CVE-2026-12328 affects Mozilla Firefox and Mozilla Thunderbird applications, specifically older versions mentioned in the advisory.

4

What are the potential risks of CVE-2026-12328?

The potential risks of CVE-2026-12328 include memory corruption that could allow attackers to execute arbitrary code.

5

When was CVE-2026-12328 published?

CVE-2026-12328 was published on June 16, 2026.

Company

Resources

Contact

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