RHSA-2026:39142: Important: thunderbird security update

Published Jul 14, 2026
·
Updated

Important: thunderbird security update

Other sources

Mozilla Thunderbird is a standalone mail and newsgroup client.Security Fix(es): firefox: thunderbird: Sandbox escape in the DOM: Workers component (CVE-2026-12294) firefox: thunderbird: Information disclosure, sandbox escape in the Security: Process Sandboxing component (CVE-2026-12313) firefox: thunderbird: Information disclosure, sandbox escape in the Security: Process Sandboxing component (CVE-2026-12311) firefox: thunderbird: Memory safety bug fixed in Thunderbird ESR 140.12 (CVE-2026-12290) firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.12, Thunderbird ESR 140.12, Firefox 152 and Thunderbird 152 (CVE-2026-12327) firefox: thunderbird: JIT miscompilation in the DOM: Core & HTML component (CVE-2026-12299) firefox: thunderbird: Memory safety bug fixed in Thunderbird ESR 140.12 (CVE-2026-12329) firefox: thunderbird: Memory safety bug fixed in Thunderbird ESR 140.12 (CVE-2026-12312) firefox: thunderbird: Mitigation bypass in the DOM: Security component (CVE-2026-12302) firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 115.37, Firefox ESR 140.12, Thunderbird ESR 140.12, Firefox 152 and Thunderbird 152 (CVE-2026-12328) firefox: thunderbird: Incorrect boundary conditions in the Internationalization component (CVE-2026-12330) firefox: thunderbird: Memory safety bug fixed in Thunderbird ESR 140.12 (CVE-2026-12314) firefox: thunderbird: Memory safety bug fixed in Thunderbird ESR 140.12 (CVE-2026-12309) firefox: thunderbird: Memory safety bug fixed in Thunderbird ESR 140.12 (CVE-2026-12310) firefox: thunderbird: Denial-of-service in the Graphics: ImageLib component (CVE-2026-12325) firefox: thunderbird: Sandbox escape in the DOM: Navigation component (CVE-2026-12295) firefox: thunderbird: Privilege escalation in the Graphics: WebRender component (CVE-2026-12289) firefox: thunderbird: Mitigation bypass in the DOM: Security component (CVE-2026-12315) firefox: thunderbird: Sandbox escape in the Security: Process Sandboxing component (CVE-2026-12296) firefox: thunderbird: Memory safety bug fixed in Thunderbird ESR 140.12 (CVE-2026-12306) firefox: thunderbird: Memory safety bug fixed in Thunderbird ESR 140.12 (CVE-2026-12307) firefox: thunderbird: Sandbox escape due to incorrect boundary conditions in the Networking component (CVE-2026-12297) firefox: thunderbird: Memory safety bug fixed in Thunderbird ESR 140.12 (CVE-2026-12305) firefox: thunderbird: Incorrect boundary conditions in the Web Audio component (CVE-2026-12292) firefox: thunderbird: Memory safety bug fixed in Thunderbird ESR 140.12 (CVE-2026-12308) firefox: thunderbird: Incorrect boundary conditions in the Graphics: CanvasWebGL component (CVE-2026-12324) firefox: thunderbird: Same-origin policy bypass in the Networking: Cookies component (CVE-2026-12304) firefox: thunderbird: Use-after-free in the Networking: HTTP component (CVE-2026-12291) firefox: thunderbird: Memory safety bug fixed in Firefox ESR 140.12 (CVE-2026-12298) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

— Red Hat

Affected Software

11 affected componentsFixes available
Red Hat Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions
Red Hat Red Hat Enterprise Linux Server - TUS
Red Hat Red Hat Enterprise Linux for x86_64 - Extended Life Cycle Long Life
Red Hat Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
redhat/thunderbird<140.12.0-1.el8_8
140.12.0-1.el8_8
redhat/thunderbird<140.12.0-1.el8_8
140.12.0-1.el8_8
redhat/thunderbird-debuginfo<140.12.0-1.el8_8
140.12.0-1.el8_8
redhat/thunderbird-debugsource<140.12.0-1.el8_8
140.12.0-1.el8_8
redhat/thunderbird<140.12.0-1.el8_8
140.12.0-1.el8_8
redhat/thunderbird-debuginfo<140.12.0-1.el8_8
140.12.0-1.el8_8
redhat/thunderbird-debugsource<140.12.0-1.el8_8
140.12.0-1.el8_8

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade redhat/thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12.0-1.el8_8
  2. Upgrade

    Upgrade redhat/thunderbird-debuginfo to a version that resolves this vulnerability.

    Fixed in 140.12.0-1.el8_8
  3. Upgrade

    Upgrade redhat/thunderbird-debugsource to a version that resolves this vulnerability.

    Fixed in 140.12.0-1.el8_8
  4. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12290
  5. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12305
  6. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12306
  7. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12307
  8. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12308
  9. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12309
  10. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12310
  11. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12312
  12. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12314
  13. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12329
  14. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12294
  15. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12311
  16. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12313
  17. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12324
  18. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12330
  19. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12292
  20. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12298
  21. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12325
  22. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12299
  23. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12328
  24. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12327
  25. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 152Patch CVE-2026-12328
  26. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 152Patch CVE-2026-12327
  27. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12302
  28. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12315
  29. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12289
  30. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12304
  31. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12297
  32. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12295
  33. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12296
  34. Upgrade

    Upgrade thunderbird to a version that resolves this vulnerability.

    Fixed in 140.12Patch CVE-2026-12291

Event History

Jul 14, 2026
Advisory Published
via Red Hat·12:00 AM
Data Sourced
via Red Hat·12:00 AM
RemedyDescriptionAffected Software
Advisory Published
via Red Hat·08:45 AM
Data Sourced
via Red Hat·08:45 AM
Severity
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 RHSA-2026:39142?

The severity of RHSA-2026:39142 is classified as high with a CVSS score of 7.

2

What vulnerabilities are addressed in RHSA-2026:39142?

RHSA-2026:39142 addresses a sandbox escape in the DOM: Workers component and an information disclosure vulnerability in security process sandboxing.

3

How do I fix RHSA-2026:39142?

To fix RHSA-2026:39142, update your Mozilla Thunderbird to the latest security patch provided by Red Hat.

4

Which systems are affected by RHSA-2026:39142?

RHSA-2026:39142 affects Red Hat Enterprise Linux systems that utilize Mozilla Thunderbird.

5

What is the risk associated with RHSA-2026:39142?

The risk associated with RHSA-2026:39142 is categorized as 33, indicating a significant potential threat to system security.

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