An update for firefox is now available for Red Hat Enterprise Linux 10.

Red Hat Product Security has rated this update as having a security impact of
Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Mozilla Firefox is an open-source web browser, designed for standards
compliance, performance, and portability.

Security Fix(es):

* 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.

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CVE-2026-15718
CVE-2026-15719: Trust Boundary Violation (CWE-501)
CVE-2026-16349: Origin Validation Error (CWE-346)
CVE-2026-16350
CVE-2026-16351: Expired Pointer Dereference (CWE-825)
CVE-2026-16352: Missing Release of Resource after Effective Lifetime (CWE-772)
CVE-2026-16353: NULL Pointer Dereference (CWE-476)
CVE-2026-16354: Insertion of Sensitive Information Into Sent Data (CWE-201)
CVE-2026-16355
CVE-2026-16356
CVE-2026-16357: Out-of-bounds Write (CWE-787)
CVE-2026-16358: Context Switching Race Condition (CWE-368)
CVE-2026-16359: Buffer Copy without Checking Size of Input ('Classic Buffer
Overflow') (CWE-120)
CVE-2026-16360: Buffer Copy without Checking Size of Input ('Classic Buffer
Overflow') (CWE-120)
CVE-2026-16361
CVE-2026-16362: Expired Pointer Dereference (CWE-825)
CVE-2026-16363: Compiler Optimization Removal or Modification of
Security-critical Code (CWE-733)
CVE-2026-16368: Out-of-bounds Write (CWE-787)
CVE-2026-16369: Integer Overflow or Wraparound (CWE-190)
CVE-2026-16371: Incorrect Privilege Assignment (CWE-266)
CVE-2026-16374: Insertion of Sensitive Information Into Debugging Code
(CWE-215)
CVE-2026-16375
CVE-2026-16377
CVE-2026-16379: Improper Isolation or Compartmentalization (CWE-653)
CVE-2026-16381: Origin Validation Error (CWE-346)
CVE-2026-16383: Reliance on Untrusted Inputs in a Security Decision (CWE-807)
CVE-2026-16387: Trust Boundary Violation (CWE-501)
CVE-2026-16390
CVE-2026-16391
CVE-2026-16396: Incorrect Privilege Assignment (CWE-266)
CVE-2026-16405: Insertion of Sensitive Information Into Sent Data (CWE-201)
CVE-2026-16412: Out-of-bounds Write (CWE-787)