RHSA-2026:54339: Important: firefox security update

Published Aug 12, 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): libaom: libaom: heap buffer overflow in AV1 encoder first-pass stats buffer via LAP mode (CVE-2026-56208) firefox: thunderbird: Site isolation issue in the DOM: Navigation component (CVE-2026-15719) firefox: thunderbird: Invalid pointer in the JavaScript: WebAssembly component (CVE-2026-15718) firefox: thunderbird: Mitigation bypass in the Enterprise Policies component (CVE-2026-16390) firefox: thunderbird: Incorrect boundary conditions in the Audio/Video: cubeb component (CVE-2026-16350) firefox: thunderbird: Information disclosure in the Storage: IndexedDB component (CVE-2026-16391) firefox: thunderbird: Site isolation issue in the Networking: HTTP component (CVE-2026-16375) firefox: thunderbird: Sandbox escape due to use-after-free in the Disability Access APIs component (CVE-2026-16356) firefox: thunderbird: JIT miscompilation in the JavaScript: WebAssembly component (CVE-2026-16363) firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.13 and Firefox 153 (CVE-2026-16412) firefox: thunderbird: Same-origin policy bypass in the Networking: DNS component (CVE-2026-16381) firefox: thunderbird: JIT miscompilation in the JavaScript Engine: JIT component (CVE-2026-16355) firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 115.38 and Firefox ESR 140.13 (CVE-2026-16361) firefox: thunderbird: Sandbox escape due to use-after-free in the Disability Access APIs component (CVE-2026-16352) firefox: thunderbird: Incorrect boundary conditions in the JavaScript: WebAssembly component (CVE-2026-16368) firefox: thunderbird: Mitigation bypass in the PDF Viewer component (CVE-2026-16377) firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 115.38, Firefox ESR 140.13 and Firefox 153 (CVE-2026-16360) firefox: thunderbird: Use-after-free in the WebRTC: Audio/Video component (CVE-2026-16362) firefox: thunderbird: Site isolation issue in the Graphics: WebRender component (CVE-2026-16358) firefox: thunderbird: Site isolation issue in the Networking component (CVE-2026-16387) firefox: thunderbird: Same-origin policy bypass in the DOM: Navigation component (CVE-2026-16349) firefox: thunderbird: Incorrect boundary conditions in the Graphics component (CVE-2026-16357) firefox: thunderbird: Sandbox escape due to use-after-free in the DOM: Navigation component (CVE-2026-16351) firefox: thunderbird: Privilege escalation in the DOM: Navigation component (CVE-2026-16371) firefox: thunderbird: Privilege escalation in the DOM: Content Processes component (CVE-2026-16379) firefox: thunderbird: Information disclosure in the Graphics: ImageLib component (CVE-2026-16354) firefox: thunderbird: Information disclosure in the Framework component in DevTools (CVE-2026-16374) firefox: thunderbird: Incorrect boundary conditions in the Audio/Video: GMP component (CVE-2026-16359) firefox: thunderbird: Mitigation bypass in the DOM: Networking component (CVE-2026-16383) firefox: thunderbird: Integer overflow in the JavaScript: WebAssembly component (CVE-2026-16369) firefox: thunderbird: Invalid pointer in the DOM: Bindings (WebIDL) component (CVE-2026-16353) firefox: thunderbird: Privilege escalation in WebExtensions (CVE-2026-16396) firefox: thunderbird: Information disclosure in the Networking: WebSockets component (CVE-2026-16405) 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 Server - TUS
Red Hat Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
Red Hat Red Hat Enterprise Linux for x86_64 - Extended Life Cycle Long Life
Red Hat Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions
redhat/firefox<140.13.0-1.el8_8
140.13.0-1.el8_8
redhat/firefox<140.13.0-1.el8_8
140.13.0-1.el8_8
redhat/firefox-debuginfo<140.13.0-1.el8_8
140.13.0-1.el8_8
redhat/firefox-debugsource<140.13.0-1.el8_8
140.13.0-1.el8_8
redhat/firefox<140.13.0-1.el8_8
140.13.0-1.el8_8
redhat/firefox-debuginfo<140.13.0-1.el8_8
140.13.0-1.el8_8
redhat/firefox-debugsource<140.13.0-1.el8_8
140.13.0-1.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 140.13.0-1.el8_8
  2. Upgrade

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

    Fixed in 140.13.0-1.el8_8
  3. Upgrade

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

    Fixed in 140.13.0-1.el8_8
  4. Upgrade

    Upgrade firefox ESR 115.38 to a version that resolves this vulnerability.

    Fixed in 115.38Patch CVE-2026-16361
  5. Upgrade

    Upgrade firefox ESR 140.13 to a version that resolves this vulnerability.

    Fixed in 140.13Patch CVE-2026-16361
  6. Upgrade

    Upgrade firefox ESR 115.38 to a version that resolves this vulnerability.

    Fixed in 115.38Patch CVE-2026-16360
  7. Upgrade

    Upgrade firefox ESR 140.13 to a version that resolves this vulnerability.

    Fixed in 140.13Patch CVE-2026-16360
  8. Upgrade

    Upgrade firefox 153 to a version that resolves this vulnerability.

    Fixed in 153Patch CVE-2026-16360
  9. Upgrade

    Upgrade firefox ESR 140.13 to a version that resolves this vulnerability.

    Fixed in 140.13Patch CVE-2026-16412
  10. Upgrade

    Upgrade firefox 153 to a version that resolves this vulnerability.

    Fixed in 153Patch CVE-2026-16412
  11. Upgrade

    Upgrade libaom to a version that resolves this vulnerability.

    Patch CVE-2026-56208

Event History

Aug 12, 2026
Advisory Published
via Red Hat·12:00 AM
Data Sourced
via Red Hat·12:00 AM
RemedyDescriptionAffected Software
Advisory Published
via Red Hat·12:02 PM
Data Sourced
via Red Hat·12:02 PM
Severity
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Frequently Asked Questions

1

What is the severity of RHSA-2026:54339?

The severity of RHSA-2026:54339 is classified as high with a score of 7.

2

What software is affected by RHSA-2026:54339?

RHSA-2026:54339 affects various versions of Red Hat Enterprise Linux Server including TUS, Power LE for SAP Solutions, and Extended Life Cycle Long Life.

3

How do I fix RHSA-2026:54339?

To fix RHSA-2026:54339, update your system to the latest version of the affected Red Hat Enterprise Linux packages.

4

What vulnerabilities does RHSA-2026:54339 address?

RHSA-2026:54339 addresses security flaws in Firefox that could potentially allow for exploitation.

5

When was RHSA-2026:54339 published?

RHSA-2026:54339 was published on August 12, 2026.

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