RHSA-2026:36103: Important: firefox security update

Published Jul 7, 2026
·
Updated

Important: firefox security update

Other sources

Mozilla Firefox is an open-source web browser, designed for standards compliance, performance, and portability.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 for x86_64 - Extended Update Support Extension
Red Hat Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
Red Hat Red Hat Enterprise Linux Server - TUS
redhat/firefox<140.12.0-1.el8_8
140.12.0-1.el8_8
redhat/firefox<140.12.0-1.el8_8
140.12.0-1.el8_8
redhat/firefox-debuginfo<140.12.0-1.el8_8
140.12.0-1.el8_8
redhat/firefox-debugsource<140.12.0-1.el8_8
140.12.0-1.el8_8
redhat/firefox<140.12.0-1.el8_8
140.12.0-1.el8_8
redhat/firefox-debuginfo<140.12.0-1.el8_8
140.12.0-1.el8_8
redhat/firefox-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/firefox to a version that resolves this vulnerability.

    Fixed in 140.12.0-1.el8_8
  2. Upgrade

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

    Fixed in 140.12.0-1.el8_8
  3. Upgrade

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

    Fixed in 140.12.0-1.el8_8
  4. Upgrade

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    Upgrade Mozilla Firefox ESR / Mozilla Thunderbird ESR / Firefox 152 / Thunderbird 152 to a version that resolves this vulnerability.

    Patch CVE-2026-12328
  16. Upgrade

    Upgrade Mozilla Firefox ESR / Mozilla Thunderbird ESR / Firefox 152 / Thunderbird 152 to a version that resolves this vulnerability.

    Patch CVE-2026-12327
  17. Upgrade

    Upgrade Mozilla Firefox / Mozilla Thunderbird to a version that resolves this vulnerability.

    Patch CVE-2026-12325
  18. Upgrade

    Upgrade Mozilla Firefox / Mozilla Thunderbird to a version that resolves this vulnerability.

    Patch CVE-2026-12324
  19. Upgrade

    Upgrade Mozilla Firefox / Mozilla Thunderbird to a version that resolves this vulnerability.

    Patch CVE-2026-12330
  20. Upgrade

    Upgrade Mozilla Firefox / Mozilla Thunderbird to a version that resolves this vulnerability.

    Patch CVE-2026-12292
  21. Upgrade

    Upgrade Mozilla Firefox / Mozilla Thunderbird to a version that resolves this vulnerability.

    Patch CVE-2026-12311
  22. Upgrade

    Upgrade Mozilla Firefox / Mozilla Thunderbird to a version that resolves this vulnerability.

    Patch CVE-2026-12313
  23. Upgrade

    Upgrade Mozilla Firefox / Mozilla Thunderbird to a version that resolves this vulnerability.

    Patch CVE-2026-12299
  24. Upgrade

    Upgrade Mozilla Firefox / Mozilla Thunderbird to a version that resolves this vulnerability.

    Patch CVE-2026-12302
  25. Upgrade

    Upgrade Mozilla Firefox / Mozilla Thunderbird to a version that resolves this vulnerability.

    Patch CVE-2026-12315
  26. Upgrade

    Upgrade Mozilla Firefox / Mozilla Thunderbird to a version that resolves this vulnerability.

    Patch CVE-2026-12289
  27. Upgrade

    Upgrade Mozilla Firefox / Mozilla Thunderbird to a version that resolves this vulnerability.

    Patch CVE-2026-12304
  28. Upgrade

    Upgrade Mozilla Firefox / Mozilla Thunderbird to a version that resolves this vulnerability.

    Patch CVE-2026-12297
  29. Upgrade

    Upgrade Mozilla Firefox / Mozilla Thunderbird to a version that resolves this vulnerability.

    Patch CVE-2026-12295
  30. Upgrade

    Upgrade Mozilla Firefox / Mozilla Thunderbird to a version that resolves this vulnerability.

    Patch CVE-2026-12296
  31. Upgrade

    Upgrade Mozilla Firefox / Mozilla Thunderbird to a version that resolves this vulnerability.

    Patch CVE-2026-12291
  32. Upgrade

    Upgrade Mozilla Firefox / Mozilla Thunderbird to a version that resolves this vulnerability.

    Patch CVE-2026-12294

Event History

Jul 7, 2026
Advisory Published
via Red Hat·12:00 AM
Data Sourced
via Red Hat·12:00 AM
RemedyDescriptionAffected Software
Advisory Published
via Red Hat·06:12 AM
Data Sourced
via Red Hat·06:12 AM
Severity
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Frequently Asked Questions

1

What is the severity of RHSA-2026:36103?

The severity of RHSA-2026:36103 is classified as high, with a score of 7.

2

What vulnerabilities does RHSA-2026:36103 address?

RHSA-2026:36103 addresses issues including a sandbox escape in the DOM: Workers component and information disclosure vulnerabilities.

3

How do I fix RHSA-2026:36103?

To fix RHSA-2026:36103, update your Mozilla Firefox installation to the latest version provided by Red Hat.

4

What software is affected by RHSA-2026:36103?

RHSA-2026:36103 affects Red Hat Firefox, including related packages like firefox-debuginfo and firefox-debugsource.

5

What is the risk associated with RHSA-2026:36103?

The risk associated with RHSA-2026:36103 is rated at 33, indicating a significant potential for exploitation.

Company

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