# CVE-2026-109740: firefox: Mozilla Firefox is an open-source web browser, designed for standards compliance, performance, and portability. Secu... CVE-2026-109740 is fixed in 5 products on 1 platform, first by RHSA-2026:89756, released October 31, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-109740 - Priority: High - CVSS: 8.2 (Important) - EPSS: 0.0035 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Oct 13, 2026 ## Description Mozilla Firefox is an open-source web browser, designed for standards compliance, performance, and portability. Security Fix(es): * libexpat: denial of service via crafted XML input (CVE-2026-45186) * 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: Sandbox escape, site isolation issue due to incorrect boundary conditions, use-after-free in the Networking component (CVE-2026-109705) * firefox: Use-after-free in the Audio/Video: Playback component (CVE-2026-109738) * 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: JIT miscompilation in the JavaScript Engine: JIT component (CVE-2026-109733) * 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: Sandbox escape due to use-after-free in the Networking component (CVE-2026-109707) * firefox: JIT miscompilation in the JavaScript: WebAssembly component (CVE-2026-109720) * 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: Use-after-free in the DOM: Streams component (CVE-2026-109732) * 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: Use-after-free in the DOM: Animation component (CVE-2026-109728) * 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): * Firefox ESR 153 rebase [rhel-8.10.z] (JIRA:RHEL-175143) 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. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | MozillaFirefox opensuse-leap 16.0 | 153.5.0-160000.1.1 | [OPENSUSE-SU-2026:22139-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22139-1.md) | Nov 7, 2026 | | Linux | MozillaFirefox sles 15.6 | 153.5.0-150400.157.16.1 | [SUSE-SU-2026:4834-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4834-1.md) | Nov 7, 2026 | | Linux | MozillaFirefox sles 15.7 | 153.5.0-150400.157.16.1 | [SUSE-SU-2026:4834-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4834-1.md) | Nov 7, 2026 | | Linux | MozillaFirefox sles 16.0 | 153.5.0-160000.1.1 | [SUSE-SU-2026:24260-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24260-1.md) | Nov 7, 2026 | | Linux | MozillaThunderbird sles 15.7 | 153.5.0-150400.13.9.1 | [SUSE-SU-2026:4736-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4736-1.md) | Nov 7, 2026 | | Linux | firefox RHEL 10 | 153.5.0-1.el10_2 | [RHSA-2026:89758](https://patchblox.com/security/data/fix/linux/rhsa-2026-89758.md) | Oct 31, 2026 | | Linux | firefox RHEL 8 | 0:153.5.0-1.el8_10 | [RHSA-2026:89756](https://patchblox.com/security/data/fix/linux/rhsa-2026-89756.md) | Oct 31, 2026 | | Linux | firefox RHEL 9 | 0:153.5.0-1.el9_8 | [RHSA-2026:89757](https://patchblox.com/security/data/fix/linux/rhsa-2026-89757.md) | Oct 31, 2026 | | Linux | firefox almalinux 10 | 153.5.0-1.el10_2 | [ALSA-2026:89758](https://patchblox.com/security/data/fix/linux/alsa-2026-89758.md) | Nov 7, 2026 | | Linux | firefox almalinux 8 | 153.5.0-1.el8_10 | [ALSA-2026:89756](https://patchblox.com/security/data/fix/linux/alsa-2026-89756.md) | Nov 7, 2026 | | Linux | firefox almalinux 9 | 153.5.0-1.el9_8 | [ALSA-2026:89757](https://patchblox.com/security/data/fix/linux/alsa-2026-89757.md) | Nov 7, 2026 | | Linux | firefox ol 10 | 0:153.5.0-1.0.1.el10_2 | [ELSA-2026-89758](https://patchblox.com/security/data/fix/linux/elsa-2026-89758.md) | Nov 7, 2026 | | Linux | firefox ol 8 | 0:153.5.0-1.0.1.el8_10 | [ELSA-2026-89756](https://patchblox.com/security/data/fix/linux/elsa-2026-89756.md) | Nov 7, 2026 | | Linux | firefox ol 9 | 0:153.5.0-1.0.1.el9_8 | [ELSA-2026-89757](https://patchblox.com/security/data/fix/linux/elsa-2026-89757.md) | Nov 7, 2026 | | Linux | firefox rocky 10 | 0:153.5.0-1.el10_2 | [RLSA-2026:89758](https://patchblox.com/security/data/fix/linux/rlsa-2026-89758.md) | Nov 7, 2026 | | Linux | firefox rocky 8 | 0:153.5.0-1.el8_10 | [RLSA-2026:89756](https://patchblox.com/security/data/fix/linux/rlsa-2026-89756.md) | Nov 7, 2026 | | Linux | firefox rocky 9 | 0:153.5.0-1.el9_8 | [RLSA-2026:89757](https://patchblox.com/security/data/fix/linux/rlsa-2026-89757.md) | Nov 7, 2026 | | Linux | firefox-x11 RHEL 9 | 0:153.5.0-1.el9_8 | [RHSA-2026:89757](https://patchblox.com/security/data/fix/linux/rhsa-2026-89757.md) | Oct 31, 2026 | | Linux | firefox-x11 almalinux 9 | 153.5.0-1.el9_8 | [ALSA-2026:89757](https://patchblox.com/security/data/fix/linux/alsa-2026-89757.md) | Nov 7, 2026 | | Linux | firefox-x11 ol 9 | 0:153.5.0-1.0.1.el9_8 | [ELSA-2026-89757](https://patchblox.com/security/data/fix/linux/elsa-2026-89757.md) | Nov 7, 2026 | | Linux | thunderbird RHEL 9 | 0:153.5.0-1.el9_8 | [RHSA-2026:93443](https://patchblox.com/security/data/fix/linux/rhsa-2026-93443.md) | Nov 3, 2026 | | Linux | thunderbird almalinux 9 | 153.5.0-1.el9_8.alma.1 | [ALSA-2026:93443](https://patchblox.com/security/data/fix/linux/alsa-2026-93443.md) | Nov 7, 2026 | | Linux | thunderbird ol 9 | 0:153.5.0-1.0.1.el9_8 | [ELSA-2026-93443](https://patchblox.com/security/data/fix/linux/elsa-2026-93443.md) | Nov 7, 2026 | | Linux | thunderbird rocky 9 | 0:153.5.0-1.el9_8 | [RLSA-2026:93443](https://patchblox.com/security/data/fix/linux/rlsa-2026-93443.md) | Nov 7, 2026 | --- Data as of 2026-11-09T13:31:49Z UTC. 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