Not ratedosv:RLSA-2026:99112

    Important: firefox security update

    Published Sources: OSV

    Share

    What is affected, what to do

    The available sources name no fixed version. Check the vendor guidance and the linked original advisory.

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    —

    XIEM Effective CVSS

    No value is available for this vulnerability.

    —

    CVSS v3

    No value is available for this vulnerability.

    —

    EPSS score

    No value is available for this vulnerability.

    Show all metrics
    Severity
    Not rated
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    30.00 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

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

    Security Fix(es):

    • firefox: thunderbird: Use-after-free in the JavaScript: GC component (CVE-2026-118007)

    • firefox: thunderbird: Sandbox escape due to use-after-free in the XPCOM component (CVE-2026-118021)

    • firefox: thunderbird: Use-after-free in the Graphics: Text component (CVE-2026-118024)

    • firefox: thunderbird: Race condition, use-after-free in the DOM: File component (CVE-2026-118019)

    • firefox: thunderbird: Use-after-free in the Audio/Video component (CVE-2026-124860)

    • firefox: thunderbird: Site isolation issue in the DOM: Navigation component (CVE-2026-124914)

    • firefox: thunderbird: Use-after-free in the DOM: Core & HTML component (CVE-2026-124869)

    • firefox: thunderbird: Privilege escalation in the DOM: Navigation component (CVE-2026-124854)

    • firefox: thunderbird: Use-after-free in the Layout: Positioned component (CVE-2026-124877)

    • firefox: thunderbird: Sandbox escape due to use-after-free in the Widget: Gtk component (CVE-2026-124917)

    • firefox: thunderbird: Incorrect boundary conditions in the DOM: Selection component (CVE-2026-124891)

    • firefox: thunderbird: Use-after-free in the Graphics: Canvas2D component (CVE-2026-124857)

    • firefox: thunderbird: Information disclosure in the Security: RLBox component (CVE-2026-124941)

    • firefox: thunderbird: Sandbox escape in the DOM: Navigation component (CVE-2026-124855)

    • firefox: thunderbird: Spoofing issue in the Security component (CVE-2026-124934)

    • firefox: thunderbird: Sandbox escape due to incorrect boundary conditions in the Graphics: Text component (CVE-2026-124853)

    • firefox: thunderbird: Sandbox escape in the DOM: Navigation component (CVE-2026-124905)

    • firefox: thunderbird: Sandbox escape due to incorrect boundary conditions in the Storage: Cache API component (CVE-2026-124859)

    • firefox: thunderbird: Use-after-free in the CSS Parsing and Computation component (CVE-2026-124881)

    • firefox: thunderbird: Use-after-free in the DOM: Core & HTML component (CVE-2026-124862)

    • firefox: thunderbird: Use-after-free in the CSS Parsing and Computation component (CVE-2026-124882)

    • firefox: thunderbird: Information disclosure in the Private Browsing component (CVE-2026-124909)

    • firefox: thunderbird: Use-after-free in the CSS Parsing and Computation component (CVE-2026-124876)

    • firefox: thunderbird: Use-after-free in the DOM: Workers component (CVE-2026-124893)

    • firefox: thunderbird: Use-after-free in the Graphics: WebRender component (CVE-2026-124906)

    • firefox: thunderbird: Incorrect boundary conditions in the Layout: Text and Fonts component (CVE-2026-124887)

    • firefox: thunderbird: Mitigation bypass in the WebExtensions component (CVE-2026-124910)

    • firefox: thunderbird: Privilege escalation in the Nimbus Desktop Client component (CVE-2026-124951)

    • firefox: thunderbird: Use-after-free in the Audio/Video component (CVE-2026-124865)

    • firefox: thunderbird: Incorrect boundary conditions, use-after-free in the Graphics component (CVE-2026-124948)

    • firefox: thunderbird: Undefined behavior in the WebRTC: Networking component (CVE-2026-124935)

    • firefox: thunderbird: Incorrect boundary conditions in the DOM: CSS Object Model component (CVE-2026-124875)

    • firefox: thunderbird: Sandbox escape due to use-after-free in the IPC component (CVE-2026-124903)

    • firefox: thunderbird: Incorrect boundary conditions in the Networking: HTTP component (CVE-2026-124856)

    • firefox: thunderbird: Use-after-free in the Networking: Cookies component (CVE-2026-124894)

    • firefox: thunderbird: Use-after-free in the Storage: localStorage & sessionStorage component (CVE-2026-124895)

    • firefox: thunderbird: Use-after-free in the Graphics: Text component (CVE-2026-124885)

    • firefox: thunderbird: Use-after-free in the Layout: Text and Fonts component (CVE-2026-124899)

    • firefox: thunderbird: Sandbox escape in the Console component (CVE-2026-124933)

    • firefox: thunderbird: Use-after-free in the Layout component (CVE-2026-124866)

    • firefox: thunderbird: Use-after-free in the DOM: Core & HTML component (CVE-2026-124883)

    • firefox: thunderbird: Information disclosure in the Layout: Form Controls component (CVE-2026-124929)

    • firefox: thunderbird: Incorrect boundary conditions in the JavaScript: GC component (CVE-2026-124870)

    • firefox: thunderbird: Site isolation issue in the Graphics: WebRender component (CVE-2026-124927)

    • firefox: thunderbird: Incorrect boundary conditions in the Graphics: WebGPU component (CVE-2026-124915)

    • firefox: thunderbird: Use-after-free in the DOM: Core & HTML component (CVE-2026-124890)

    • firefox: thunderbird: Information disclosure in the Address Bar component (CVE-2026-124930)

    • firefox: thunderbird: Invalid pointer in the Layout: Text and Fonts component (CVE-2026-124886)

    • firefox: thunderbird: Use-after-free in the DOM: HTML Parser component (CVE-2026-124858)

    • firefox: thunderbird: Privilege escalation, sandbox escape due to use-after-free in the Graphics: CanvasWebGL component (CVE-2026-124907)

    • firefox: thunderbird: Invalid pointer in the DOM: Editor component (CVE-2026-124873)

    • firefox: thunderbird: Spoofing issue in the DOM: Security component (CVE-2026-124912)

    • firefox: thunderbird: Same-origin policy bypass in the Networking: HTTP component (CVE-2026-124874)

    • firefox: thunderbird: Use-after-free in the JavaScript: GC component (CVE-2026-124892)

    • firefox: thunderbird: Invalid pointer in the DOM: Streams component (CVE-2026-124942)

    • firefox: thunderbird: Use-after-free in the CSS Transitions and Animations component (CVE-2026-124922)

    • firefox: thunderbird: Privilege escalation due to incorrect boundary conditions in the Graphics: WebRender component (CVE-2026-124918)

    • firefox: thunderbird: Use-after-free in the JavaScript: GC component (CVE-2026-124884)

    • firefox: thunderbird: Incorrect boundary conditions in the DOM: Core & HTML component (CVE-2026-124868)

    • firefox: thunderbird: Privilege escalation due to use-after-free in the WebRTC: Networking component (CVE-2026-124919)

    • firefox: thunderbird: Incorrect boundary conditions in the Graphics: WebRender component (CVE-2026-124924)

    • firefox: thunderbird: Same-origin policy bypass due to race condition in the Audio/Video component (CVE-2026-124902)

    • firefox: thunderbird: Invalid pointer in the Networking: Cache component (CVE-2026-124879)

    • firefox: thunderbird: Use-after-free in the Graphics component (CVE-2026-124932)

    • firefox: thunderbird: Mitigation bypass in the File Handling component (CVE-2026-124940)

    • firefox: thunderbird: Same-origin policy bypass in the DOM: Core & HTML component (CVE-2026-124931)

    • firefox: thunderbird: Incorrect boundary conditions in the WebRTC component (CVE-2026-124926)

    • firefox: thunderbird: Use-after-free in the DOM: HTML Parser component (CVE-2026-124863)

    • firefox: thunderbird: Use-after-free in the CSS Parsing and Computation component (CVE-2026-124889)

    • firefox: thunderbird: Site isolation issue in the Networking component (CVE-2026-124913)

    • firefox: thunderbird: Use-after-free in the JavaScript: GC component (CVE-2026-124897)

    • firefox: thunderbird: Sandbox escape due to use-after-free in the DOM: Service Workers component (CVE-2026-124864)

    • firefox: thunderbird: Use-after-free in the Cycle Collector component (CVE-2026-124872)

    • firefox: thunderbird: Use-after-free in the DOM: Core & HTML component (CVE-2026-124880)

    • firefox: thunderbird: Invalid pointer in the Layout: Text and Fonts component (CVE-2026-124896)

    • firefox: thunderbird: Other issue in the Networking: JAR component (CVE-2026-124901)

    • firefox: thunderbird: Incorrect boundary conditions in the Layout: Text and Fonts component (CVE-2026-124888)

    • firefox: thunderbird: Mitigation bypass in the Add-ons Manager component (CVE-2026-124938)

    • firefox: thunderbird: Sandbox escape due to use-after-free in the Audio/Video: cubeb component (CVE-2026-124861)

    • firefox: thunderbird: Use-after-free in the DOM: Editor component (CVE-2026-124898)

    • firefox: thunderbird: JIT miscompilation in the JavaScript Engine: JIT component (CVE-2026-124939)

    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.

    Source: OSV (Open Source Vulnerabilities)