HighCVE-2026-66298

    JS-view sandboxed output can synthesize keyboard events to trigger unconfirmed global shortcuts (CVE-2026-66298)

    Published Last modified Sources: CVE.org, OSV

    What is affected, what to do

    Origin Validation Error vulnerability in livebook-dev livebook allows untrusted notebook output JavaScript to trigger session-wide keyboard shortcuts, including forced evaluation of all cells and runtime restart. Livebook's JS-view feature renders notebook-defined JavaScript inside a sandboxed, cross-origin iframe specifically because that JavaScript is untrusted.

    Update Livebook to version 0.18.7, Livebook to version 0.19.9, Livebook to version 0.18.7-cuda12.

    Affected
    • Livebook lt 0.5.0..0.18.7
    • Livebook lt 0.19.0..0.19.9
    • Livebook lt 0.5.0-cuda12..0.18.7-cuda12
    • Livebook lt 0.19.0-cuda12..0.19.9-cuda12
    Fixed in
    • Livebook 0.18.7
    • Livebook 0.19.9
    • Livebook 0.18.7-cuda12
    • Livebook 0.19.9-cuda12

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

    Metrics

    8.8

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v3

    8.8

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: CVE.org, OSV

    0.3 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 18.7

    Show all metrics
    Severity
    High
    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
    69.33 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
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    8.8 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    8.8
    CVSS v4

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    8.6
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    0.3 %
    Low — model estimates < 1% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    18.7
    Elevated — this CVE ranks above at least 10% of all CVEs scored today.
    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
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-346

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    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
    High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
    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

    Origin Validation Error vulnerability in livebook-dev livebook allows untrusted notebook output JavaScript to trigger session-wide keyboard shortcuts, including forced evaluation of all cells and runtime restart. Livebook's JS-view feature renders notebook-defined JavaScript inside a sandboxed, cross-origin iframe specifically because that JavaScript is untrusted. The trusted iframe shell in iframe/priv/static/iframe/v5.html forwards every keydown event fired in its own window to the parent page without consulting Event.isTrusted, so an event synthesized by the untrusted script through window.dispatchEvent is forwarded exactly as a genuine keystroke would be. The parent-side relay in assets/js/hooks/js_view.js reconstructs and re-dispatches it on the live page with no further validation, and because assets/js/hooks/session.js registers the global shortcut handler on the document in the capture phase, that handler acts on the replicated event regardless of how it was produced. Sandboxed output JavaScript can therefore drive Livebook's session-wide keyboard shortcuts. Two of them reach LivebookWeb.SessionLive and execute immediately with no confirmation: the shortcut for queueing full evaluation runs every cell in the notebook, and the shortcut for reconnecting the runtime disconnects and reconnects it, discarding in-memory state. A third shortcut deletes the focused cell behind a confirmation dialog that the user can permanently dismiss, after which it too executes silently. Forced full evaluation is the significant consequence, because it causes the notebook's own Elixir code to run without the user choosing to evaluate anything. A user who merely opens a notebook obtained from a third party, or reached from published documentation, can have its code executed on their runtime. Livebook also mirrors cell outputs to every connected client, so a malicious output triggers in a collaborator's browser as soon as it renders. This issue affects livebook: from 0.5.0 before 0.18.7 and from 0.19.0 before 0.19.9.

    Source: NVD (NIST), cvelistv5, OSV (Open Source Vulnerabilities)

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    livebook-devlivebook
    • 0.19.0-cuda12 – < 0.19.9-cuda12
    • 0.5.0-cuda12 – < 0.18.7-cuda12
    • 0.5.0 – < 0.18.7
    • 0.19.0 – < 0.19.9
    • 0.19.9-cuda12
    • 0.18.7-cuda12
    • 0.18.7
    • 0.19.9
    livebooklivebook
    • 0.19.0 – < 0.19.9
    • 0.5.0 – < 0.18.7
    • 0.19.9
    • 0.18.7
    hexlivebook
    • 0.17.0
    • 0.19.1
    • 0.17.1
    • 0.15.1
    • 0.18.3
    • 0.18.4
    • 0.18.5
    • 0.16.1
    • 0.13.1
    • 0.11.0
    • 0.19.4
    • 0.15.4
    • 0.8.2
    • 0.11.1
    • 0.13.2
    • 0.16.2
    • 0.9.2
    • 0.18.2
    • 0.19.0
    • 0.14.0-rc.0
    • 0.14.6
    • 0.9.1
    • 0.6.1
    • 0.5.0
    • 0.19.6
    • 0.15.5
    • 0.14.4
    • 0.13.3
    • 0.15.3
    • 0.5.2
    • 0.16.3
    • 0.7.1
    • 0.16.4
    • 0.17.3
    • 0.15.2
    • 0.7.0
    • 0.9.3
    • 0.11.4
    • 0.16.0
    • 0.12.0
    • 0.6.0
    • 0.14.7
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    Vendors and products

    Weakness classes (CWE)

    • CWE-346Origin Validation Error

      Class

      The product does not properly verify that the source of data or communication is valid.

      Entry at MITRE CWE-346

    References & sources

    • github.comlivebook-dev/livebook/security/advisories/GHSA-68c2-prqg-x62gadvisory, Vendor advisory, related, Patch, Vendor advisory
    • cna.erlef.orgcves/CVE-2026-66298.htmlweb, related, Vendor advisory
    • github.comlivebook-dev/livebook/commit/296318ffdfa6e5ed7b18ad8d5a5b2af90f…fix, Patch, Patch
    • github.comlivebook-dev/livebook/commit/a552ce8f99ad348ea37061394dc950a0ce…fix, Patch, Patch
    • github.comlivebook-dev/livebook/commit/5980e5c6b71036806b3bf54101eb1d6c0f…fix, Patch, Patch
    • hex.pmpackages/livebookpackage
    • OSV (Open Source Vulnerabilities)vulnerability/EEF-CVE-2026-66298related, Third-party advisory

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. Initial analysis by NVDNVD

      Newly listed as affected:
      • Livebook (0.19.0 – before 0.19.9; 0.5.0 – before 0.18.7)

      CVSS V3.1: AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

      Show 8 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      CVSSadded
      —
      AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
      Product configurationadded
      —
      OR *cpe:2.3:a:livebook:livebook:*:*:*:*:*:*:*:* versions from (including) 0.19.0 up to (excluding) 0.19.9 *cpe:2.3:a:livebook:livebook:*:*:*:*:*:*:*:* versions from (including) 0.5.0 up to (excluding) 0.18.7
      Reference typeadded
      —
      EEF: https://cna.erlef.org/cves/CVE-2026-66298.html Types: Vendor Advisory
      Reference typeadded
      —
      EEF: https://github.com/livebook-dev/livebook/commit/296318ffdfa6e5ed7b18ad8d5a5b2af90f3cd728 Types: Patch
      Reference typeadded
      —
      EEF: https://github.com/livebook-dev/livebook/commit/5980e5c6b71036806b3bf54101eb1d6c0f50f19c Types: Patch
      Reference typeadded
      —
      EEF: https://github.com/livebook-dev/livebook/commit/a552ce8f99ad348ea37061394dc950a0cebdb33e Types: Patch
      Reference typeadded
      —
      EEF: https://github.com/livebook-dev/livebook/security/advisories/GHSA-68c2-prqg-x62g Types: Patch, Vendor Advisory
      Reference typeadded
      —
      EEF: https://osv.dev/vulnerability/EEF-CVE-2026-66298 Types: Third Party Advisory

      Source identifier: nvd@nist.gov

    2. ReceivedEEF

      CVSS V4.0: AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

      Weakness type: CWE-346

      Description added or changed

      Show 10 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      livebook, livebook, livebook
      Descriptionadded
      —
      Origin Validation Error vulnerability in livebook-dev livebook allows untrusted notebook output JavaScript to trigger session-wide keyboard shortcuts, including forced evaluation of all cells and runtime restart. Livebook's JS-view feature renders notebook-defined JavaScript inside a sandboxed, cross-origin iframe specifically because that JavaScript is untrusted. The trusted iframe shell in iframe/priv/static/iframe/v5.html forwards every keydown event fired in its own window to the parent page without consulting Event.isTrusted, so an event synthesized by the untrusted script through window.dispatchEvent is forwarded exactly as a genuine keystroke would be. The parent-side relay in assets/js/hooks/js_view.js reconstructs and re-dispatches it on the live page with no further validation, and because assets/js/hooks/session.js registers the global shortcut handler on the document in the capture phase, that handler acts on the replicated event regardless of how it was produced. Sandboxed output JavaScript can therefore drive Livebook's session-wide keyboard shortcuts. Two of them reach LivebookWeb.SessionLive and execute immediately with no confirmation: the shortcut for queueing full evaluation runs every cell in the notebook, and the shortcut for reconnecting the runtime disconnects and reconnects it, discarding in-memory state. A third shortcut deletes the focused cell behind a confirmation dialog that the user can permanently dismiss, after which it too executes silently. Forced full evaluation is the significant consequence, because it causes the notebook's own Elixir code to run without the user choosing to evaluate anything. A user who merely opens a notebook obtained from a third party, or reached from published documentation, can have its code executed on their runtime. Livebook also mirrors cell outputs to every connected client, so a malicious output triggers in a collaborator's browser as soon as it renders. This issue affects livebook: from 0.5.0 before 0.18.7 and from 0.19.0 before 0.19.9.
      CVSSadded
      —
      AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
      Weakness type (CWE)added
      —
      CWE-346
      Referenceadded
      —
      https://cna.erlef.org/cves/CVE-2026-66298.html
      Referenceadded
      —
      https://github.com/livebook-dev/livebook/commit/296318ffdfa6e5ed7b18ad8d5a5b2af90f3cd728
      Referenceadded
      —
      https://github.com/livebook-dev/livebook/commit/5980e5c6b71036806b3bf54101eb1d6c0f50f19c
      Referenceadded
      —
      https://github.com/livebook-dev/livebook/commit/a552ce8f99ad348ea37061394dc950a0cebdb33e
      Referenceadded
      —
      https://github.com/livebook-dev/livebook/security/advisories/GHSA-68c2-prqg-x62g
      Referenceadded
      —
      https://osv.dev/vulnerability/EEF-CVE-2026-66298

      Source identifier: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db

    2 NVD translations into other languages are hidden.

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