CVE-2026-16360: Memory safety bugs fixed in Thunderbird ESR 140.13 and Thunderbird 153

Published Jul 21, 2026
·
Updated

Memory safety bugs present in Firefox ESR 115.37, Firefox ESR 140.12 and Firefox 152. 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.

Other sources

Memory safety bugs present in Thunderbird ESR 140.12 and Thunderbird 152. 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.

Mozilla

Affected Software

13 affected componentsFixes available
Mozilla Firefox ESR>115.37<=115.37
Mozilla Firefox ESR>140.12<=140.12
Mozilla Firefox>152<=152
Mozilla Firefox<153
153
Mozilla Firefox ESR<115.38
115.38
Mozilla Firefox ESR<140.13
140.13
Mozilla Thunderbird<140.13
140.13
Mozilla Thunderbird<153
153
Mozilla Firefox<115.38.0
Mozilla Firefox<153.0.0
Mozilla Firefox>=128.1.0<140.13.0
Mozilla Thunderbird<140.13.0
Mozilla Thunderbird>=141.0<153.0

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 153
  2. Upgrade

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

    Fixed in 115.38
  3. Upgrade

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

    Fixed in 140.13
  4. Upgrade

    Upgrade Mozilla Firefox ESR to a version that resolves this vulnerability.

    Fixed in 115.38
  5. Upgrade

    Upgrade Mozilla Firefox ESR to a version that resolves this vulnerability.

    Fixed in 140.13
  6. Upgrade

    Upgrade Mozilla Firefox to a version that resolves this vulnerability.

    Fixed in 153
  7. Upgrade

    Upgrade Mozilla Thunderbird ESR to a version that resolves this vulnerability.

    Fixed in 140.13
  8. Upgrade

    Upgrade Mozilla Thunderbird to a version that resolves this vulnerability.

    Fixed in 153

Event History

Jul 21, 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
Updated
via Mozilla·12:00 AM
DescriptionAffected Software
CVE Published
via MITRE·12:38 PM
Data Sourced
via MITRE·12:38 PM
Description
Data Sourced
via NVD·01:17 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-2026-16360?

CVE-2026-16360 has a critical severity rating of 9.8 on the CVSS scale.

2

How do I fix CVE-2026-16360?

To mitigate CVE-2026-16360, users should upgrade to Thunderbird ESR 140.13 or Thunderbird 153.

3

What types of issues does CVE-2026-16360 address?

CVE-2026-16360 addresses memory safety bugs that could lead to memory corruption and potential arbitrary code execution.

4

Which software versions are affected by CVE-2026-16360?

CVE-2026-16360 affects Mozilla Firefox ESR 115.37, Firefox ESR 140.12, and Firefox 152.

5

What should I do if I cannot update due to compatibility issues with CVE-2026-16360?

If you're unable to update for compatibility reasons, consider assessing the use of mitigations until an upgrade is possible.

Contact

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