CVE-2026-12290: Memory safety bug fixed in Thunderbird 152

Published Jun 16, 2026
·
Updated

Memory safety bug fixed in Firefox 152. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37.

Other sources

Memory safety bug fixed in Firefox 152. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.

— NVD

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<152.0.0
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 to a version that resolves this vulnerability.

    Fixed in 152
  5. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 140.12
  6. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 115.37
  7. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 152
  8. Upgrade

    Upgrade Thunderbird 140.12 to a version that resolves this vulnerability.

    Fixed in 140.12

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·11:52 AM
Data Sourced
via MITRE·11:52 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.

Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is the severity of CVE-2026-12290?

CVE-2026-12290 has a severity rating of high with a CVSS score of 8.1.

2

How do I fix CVE-2026-12290?

To fix CVE-2026-12290, update to Thunderbird version 152 or later.

3

Which software is affected by CVE-2026-12290?

CVE-2026-12290 affects Mozilla Thunderbird, Mozilla Firefox, and Mozilla Firefox ESR.

4

What type of vulnerability is CVE-2026-12290?

CVE-2026-12290 is a memory safety bug classified under buffer overflow vulnerabilities.

5

When was CVE-2026-12290 published?

CVE-2026-12290 was published on June 16, 2026.

Company

Resources

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203
CVE-2026-12290 - Memory safety bug fixed in Thunderbird 152 - SecAlerts