RHSA-2026:99050: Important: thunderbird security, bug fix, and enhancement update

Mozilla Thunderbird is a standalone mail and newsgroup client.Security Fix(es): libexpat: denial of service via crafted XML input (CVE-2026-45186) firefox: Mitigation bypass in the Enterprise Policies component (CVE-2026-109764) firefox: Spoofing issue in the DOM: Web Serial component (CVE-2026-109770) firefox: Mitigation bypass in the File Handling component (CVE-2026-109783) firefox: thunderbird: Privilege escalation in the Application Update component (CVE-2026-109704) firefox: Use-after-free in the XML component (CVE-2026-109718) firefox: Information disclosure in the PDF Viewer component (CVE-2026-109742) firefox: Incorrect boundary conditions in the JavaScript Engine component (CVE-2026-109715) firefox: firefox: Sandbox escape via incorrect boundary conditions in Win32 widget (CVE-2026-109740) firefox: Use-after-free in the Storage: IndexedDB component (CVE-2026-109706) firefox: Use-after-free in the Crash Reporting component (CVE-2026-109713) firefox: Use-after-free in the DOM: Core & HTML component (CVE-2026-109724) firefox: Sandbox escape due to uninitialized memory in the DOM: Web Serial component (CVE-2026-109745) firefox: Mitigation bypass in the File Handling component (CVE-2026-109782) firefox: Information disclosure, privilege escalation in the Security: Process Sandboxing component (CVE-2026-109709) firefox: Use-after-free in the Audio/Video: Playback component (CVE-2026-109738) firefox: Sandbox escape due to race condition in the Networking component (CVE-2026-109757) firefox: Use-after-free in the Storage: Bucket File System component (CVE-2026-109741) firefox: Use-after-free in the JavaScript Engine: JIT component (CVE-2026-109729) firefox: Other issue in the DOM: File component (CVE-2026-109744) firefox: Incorrect boundary conditions in the JavaScript Engine component (CVE-2026-109716) firefox: Race condition, use-after-free in the Graphics: CanvasWebGL component (CVE-2026-109719) firefox: Incorrect boundary conditions in the Layout component (CVE-2026-109753) firefox: Integer overflow in the Layout: Text and Fonts component (CVE-2026-109723) firefox: Privilege escalation in the DOM: Navigation component (CVE-2026-109756) firefox: JIT miscompilation in the JavaScript Engine: JIT component (CVE-2026-109733) firefox: thunderbird: Mitigation bypass in the DOM: Security component (CVE-2026-109734) firefox: Mitigation bypass in the File Handling component (CVE-2026-109763) firefox: Sandbox escape due to incorrect boundary conditions in the Networking component (CVE-2026-109708) firefox: Use-after-free in the DOM: Bindings (WebIDL) component (CVE-2026-109717) firefox: Use-after-free in the DOM: Workers component (CVE-2026-109752) firefox: Race condition in the XPCOM component (CVE-2026-109776) firefox: Mitigation bypass in the Networking: HTTP component (CVE-2026-109760) firefox: JIT miscompilation in the JavaScript: WebAssembly component (CVE-2026-109720) firefox: Information disclosure in the Storage: IndexedDB component (CVE-2026-109777) firefox: Use-after-free in the SVG component (CVE-2026-109726) firefox: Integer overflow in the Graphics component (CVE-2026-109730) firefox: Use-after-free in the Audio/Video component (CVE-2026-109727) firefox: Mitigation bypass in the Enterprise Policies component (CVE-2026-109737) firefox: Mitigation bypass in the Enterprise Policies component (CVE-2026-109766) firefox: Use-after-free in the DOM: Streams component (CVE-2026-109732) firefox: Site isolation issue in the Networking component (CVE-2026-109759) firefox: Privilege escalation in the WebExtensions component (CVE-2026-109778) firefox: Incorrect boundary conditions in the SVG component (CVE-2026-109762) firefox: Race condition, use-after-free in the Graphics: Text component (CVE-2026-109765) firefox: Incorrect boundary conditions in the DOM: Editor component (CVE-2026-109754) firefox: Information disclosure in the Networking component (CVE-2026-109751) firefox: Use-after-free in the DOM: Core & HTML component (CVE-2026-109725) firefox: Sandbox escape due to uninitialized memory in the Graphics component (CVE-2026-109712) firefox: Use-after-free in the Graphics: Canvas2D component (CVE-2026-109711) firefox: Frame poisoning in the Layout component (CVE-2026-109736) firefox: JIT miscompilation in the JavaScript Engine: JIT component (CVE-2026-109722) firefox: Information disclosure in the Networking component (CVE-2026-109767) firefox: Denial-of-service in the WebRTC component (CVE-2026-109775) firefox: Use-after-free in the DOM: Animation component (CVE-2026-109728) firefox: Denial-of-service in the Printing: Output component (CVE-2026-109781) firefox: thunderbird: Use-after-free in the Graphics: Text component (CVE-2026-109710) firefox: thunderbird: Incorrect boundary conditions in the Graphics: Canvas2D component (CVE-2026-109731) firefox: Incorrect boundary conditions in the JavaScript Engine: JIT component (CVE-2026-109721) firefox: Privilege escalation in the Panning and Zooming component (CVE-2026-109743) Bug Fix(es) and Enhancement(s): Thunderbird ESR 153 rebase [rhel-10.0.z] (JIRA:RHEL-175204) 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