Linux · Security advisory · October 31, 2026

RHSA-2026:89758: firefox security update

RHSA-2026:89758, released October 31, 2026, fixes 29 CVEs in firefox (version 153.5.0-1.el10_2). None of them is reported as exploited. Patch Radar priority: Urgent.

Urgent
CVEs closed
29
3 rated Critical
Exploited
0
None reported
Exploitation more likely
0
Vendor assessment
Highest EPSS
0.0048
41st percentile

Priority of the 29 CVEs

Patch now 0 Urgent 3 High 26 Routine 0

Fixed package versions

ProductReleaseFixed in
firefoxRHEL 10153.5.0-1.el10_2

CVEs this fix closes

PriorityCVETitleImpactCVSSEPSSExploitation
Urgent CVE-2026-109708 firefox-esr: Sandbox escape due to incorrect boundary conditions in the Networking component 9.6 0.0033 None reported
Urgent CVE-2026-109705 thunderbird: Sandbox escape, site isolation issue due to incorrect boundary conditions, use-after-free in the Networking component 9.6 0.0033 None reported
Urgent CVE-2026-109707 firefox-esr: Sandbox escape due to use-after-free in the Networking component 9.6 0.0033 None reported
High CVE-2026-45186 In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial of service via moderately sized crafted XML input. 8.2 0.0048 None reported
High CVE-2026-109704 firefox: Privilege escalation in the Application Update component 8.2 0.0041 None reported
High CVE-2026-109730 thunderbird: Integer overflow in the Graphics component 8.8 0.0037 None reported
High CVE-2026-109740 firefox: Mozilla Firefox is an open-source web browser, designed for standards compliance, performance, and portability. Secu... 8.2 0.0035 None reported
High CVE-2026-109709 thunderbird: Information disclosure, privilege escalation in the Security: Process Sandboxing component 8.8 0.0033 None reported
High CVE-2026-77214 libexpat Heap Buffer Over-read in xmlparse.c via XML_ParseBuffer 8.2 0.0032 None reported
High CVE-2026-109715 firefox-esr: Incorrect boundary conditions in the JavaScript Engine component 8.8 0.0031 None reported
High CVE-2026-109716 firefox-esr: Incorrect boundary conditions in the JavaScript Engine component 8.8 0.0031 None reported
High CVE-2026-109722 firefox-esr: JIT miscompilation in the JavaScript Engine: JIT component 8.8 0.0031 None reported
High CVE-2026-109721 firefox-esr: Incorrect boundary conditions in the JavaScript Engine: JIT component 8.8 0.0028 None reported
High CVE-2026-109720 firefox-esr: JIT miscompilation in the JavaScript: WebAssembly component 8.8 0.0026 None reported
High CVE-2026-109729 thunderbird: Use-after-free in the JavaScript Engine: JIT component 8.2 0.0024 None reported
High CVE-2026-109732 thunderbird: Use-after-free in the DOM: Streams component 8.2 0.0024 None reported
High CVE-2026-109718 thunderbird: Use-after-free in the XML component 8.8 0.0023 None reported
High CVE-2026-109725 thunderbird: Use-after-free in the DOM: Core & HTML component 8.8 0.0023 None reported
High CVE-2026-109728 thunderbird: Use-after-free in the DOM: Animation component 8.8 0.0023 None reported
High CVE-2026-109706 thunderbird: Use-after-free in the Storage: IndexedDB component 8.2 0.0023 None reported
High CVE-2026-109726 thunderbird: Use-after-free in the SVG component 8.2 0.0023 None reported
High CVE-2026-109727 thunderbird: Use-after-free in the Audio/Video component 8.2 0.0023 None reported
High CVE-2026-109712 firefox-esr: Sandbox escape due to uninitialized memory in the Graphics component 8.8 0.0022 None reported
High CVE-2026-109711 thunderbird: Use-after-free in the Graphics: Canvas2D component 8.8 0.0022 None reported
High CVE-2026-109713 thunderbird: Use-after-free in the Crash Reporting component 8.8 0.0022 None reported
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