RHSA-2026:36102: 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

6 affected componentsFixes available
Red Hat Red Hat Enterprise Linux for x86_64 - Extended Update Support Extension
Red Hat Red Hat Enterprise Linux Server - AUS
redhat/firefox<140.12.0-1.el8_4
140.12.0-1.el8_4
redhat/firefox<140.12.0-1.el8_4
140.12.0-1.el8_4
redhat/firefox-debuginfo<140.12.0-1.el8_4
140.12.0-1.el8_4
redhat/firefox-debugsource<140.12.0-1.el8_4
140.12.0-1.el8_4

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_4
  2. Upgrade

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

    Fixed in 140.12.0-1.el8_4
  3. Upgrade

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

    Fixed in 140.12.0-1.el8_4
  4. Upgrade

    Upgrade Firefox ESR 140.12 to a version that resolves this vulnerability.

    Fixed in 140.12
  5. Upgrade

    Upgrade Thunderbird ESR 140.12 to a version that resolves this vulnerability.

    Fixed in 140.12
  6. Upgrade

    Upgrade Firefox 152 to a version that resolves this vulnerability.

    Fixed in 152
  7. Upgrade

    Upgrade Thunderbird 152 to a version that resolves this vulnerability.

    Fixed in 152

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
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-2026:36102?

The severity of RHSA-2026:36102 is high with a CVSS score of 7.

2

How do I fix RHSA-2026:36102?

To fix RHSA-2026:36102, update Mozilla Firefox to the latest version provided in the security update.

3

What vulnerabilities are addressed in RHSA-2026:36102?

RHSA-2026:36102 addresses a sandbox escape vulnerability in the Workers component and an information disclosure issue.

4

Is RHSA-2026:36102 applicable to all versions of Firefox?

RHSA-2026:36102 is specific to the Red Hat versions of Firefox and is not applicable to all general versions.

5

What components are affected by RHSA-2026:36102?

The affected components include Mozilla Firefox, Thunderbird, and their associated debuginfo and debugsource packages.

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