MediumCVE-2026-70612

    Electron: Sandboxed iframes can launch external protocol handlers (CVE-2026-70612)

    Published Last modified Sources: CVE.org, OSV

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    What is affected, what to do

    Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3, requests to open external protocol URLs from web content did not take iframe sandbox restrictions into account, so a sandboxed iframe could cause an OS-registered external application to be launched.

    Update Electron to version 39.8.8.

    Affected
    • Electron gte 40.0.0-alpha.1, < 40.9.0..*
    • Electron lt *..39.8.8
    Fixed in
    • Electron 39.8.8

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

    Metrics

    5.4

    Priority

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

    Source: NVD, CVSS v3

    5.4

    CVSS v3

    Severity Medium on the scale from 0 to 10.

    Source: CVE.org, OSV

    0.4 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 37.3

    Show all metrics
    Severity
    Medium
    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
    59.98 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
    5.4 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
    5.4
    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
    0.4 %
    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
    37.3
    High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
    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
    CISA assessment (SSVC)
    Exploitation: none known · not automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 5 August 2026
    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-284

    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
    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

    Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3, requests to open external protocol URLs from web content did not take iframe sandbox restrictions into account, so a sandboxed iframe could cause an OS-registered external application to be launched. The frame sandbox state was also not made available to the app permission handlers, affecting apps that render untrusted content in sandboxed iframes and grant the openExternal permission by default when no setPermissionRequestHandler is installed. This issue is fixed in 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3.

    Source: cvelistv5, NVD (NIST), 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
    electronelectron
    • < 39.8.8
    • ≥ 40.0.0-alpha.1, < 40.9.0
    • 39.8.8
    • —
    electronjselectron
    • 42.0.0
    • 41.0.0 – ≤ 41.2.1
    • 40.0.0 – < 40.9.0
    • < 39.8.8
    • —
    • —
    • 40.9.0
    • 39.8.8

    Vendors and products

    Weakness classes (CWE)

    • CWE-284Improper Access Control

      Pillar

      The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

      Entry at MITRE CWE-284

    References & sources

    • github.comelectron/electron/security/advisories/GHSA-p2rr-rvmm-c5fpweb, x_refsource_CONFIRM
    • github.comelectron/electron/pull/50961web, x_refsource_MISC
    • github.comelectron/electron/pull/50962web, x_refsource_MISC
    • github.comelectron/electron/pull/50963web, x_refsource_MISC
    • github.comelectron/electron/pull/50964web, x_refsource_MISC
    • github.comelectron/electron/commit/08b9d0a220e267d1a2402a44bdd01a2e9aa320…web, x_refsource_MISC
    • github.comelectron/electron/commit/2764e4c35168855f614876051823db4f58a371…web, x_refsource_MISC
    • github.comelectron/electron/commit/477dcf7afc6550715f9ec5e6f39ee38e5dd7bf…web, x_refsource_MISC
    • github.comelectron/electron/commit/c39e3d5687d57434c8d5fe814c5152efd2f631…web, x_refsource_MISC
    • github.comelectron/electronpackage
    • github.comelectron/electron/releases/tag/v39.8.8web, x_refsource_MISC
    • github.comelectron/electron/releases/tag/v40.9.0web, x_refsource_MISC
    • github.comelectron/electron/releases/tag/v41.2.1web, x_refsource_MISC
    • github.comelectron/electron/releases/tag/v42.0.0-beta.3web, x_refsource_MISC

    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

      Show 14 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Product configurationadded
      —
      OR *cpe:2.3:a:electronjs:electron:42.0.0:alpha1:*:*:*:node.js:*:* *cpe:2.3:a:electronjs:electron:42.0.0:alpha2:*:*:*:node.js:*:* *cpe:2.3:a:electronjs:electron:42.0.0:alpha3:*:*:*:node.js:*:* *cpe:2.3:a:electronjs:electron:42.0.0:alpha4:*:*:*:node.js:*:* *cpe:2.3:a:electronjs:electron:*:*:*:*:*:node.js:*:* versions up to (excluding) 39.8.8 *cpe:2.3:a:electronjs:electron:*:*:*:*:*:node.js:*:* versions from (including) 40.0.0 up to (excluding) 40.9.0 *cpe:2.3:a:electronjs:electron:*:*:*:*:*:node.js:*:* versions from (including) 41.0.0 up to (including) 41.2.1 *cpe:2.3:a:electronjs:electron:42.0.0:alpha5:*:*:*:node.js:*:* *cpe:2.3:a:electronjs:electron:42.0.0:alpha6:*:*:*:node.js:*:* *cpe:2.3:a:electronjs:electron:42.0.0:beta1:*:*:*:node.js:*:* *cpe:2.3:a:electronjs:electron:42.0.0:beta2:*:*:*:node.js:*:*
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/electron/electron/commit/08b9d0a220e267d1a2402a44bdd01a2e9aa320b5 Types: Patch
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/electron/electron/commit/2764e4c35168855f614876051823db4f58a3714a Types: Patch
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/electron/electron/commit/477dcf7afc6550715f9ec5e6f39ee38e5dd7bf39 Types: Patch
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/electron/electron/commit/c39e3d5687d57434c8d5fe814c5152efd2f631c3 Types: Patch
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/electron/electron/pull/50961 Types: Issue Tracking, Patch
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/electron/electron/pull/50962 Types: Issue Tracking, Patch
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/electron/electron/pull/50963 Types: Issue Tracking, Patch
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/electron/electron/pull/50964 Types: Issue Tracking, Patch
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/electron/electron/releases/tag/v39.8.8 Types: Release Notes
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/electron/electron/releases/tag/v40.9.0 Types: Release Notes
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/electron/electron/releases/tag/v41.2.1 Types: Release Notes
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/electron/electron/releases/tag/v42.0.0-beta.3 Types: Release Notes
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/electron/electron/security/advisories/GHSA-p2rr-rvmm-c5fp Types: Mitigation, Vendor Advisory

      Source identifier: nvd@nist.gov

    2. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: none known, automatable: no

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentadded
      —
      {"id":"CVE-2026-70612","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-08-05T19:03:22.677858Z"}

      Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

    3. ReceivedGitHub

      Show 17 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      electron
      Descriptionadded
      —
      Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3, requests to open external protocol URLs from web content did not take iframe sandbox restrictions into account, so a sandboxed iframe could cause an OS-registered external application to be launched. The frame sandbox state was also not made available to the app permission handlers, affecting apps that render untrusted content in sandboxed iframes and grant the openExternal permission by default when no setPermissionRequestHandler is installed. This issue is fixed in 39.8.8, 40.9.0, 41.2.1, and 42.0.0-beta.3.
      CVSSadded
      —
      AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
      Weakness type (CWE)added
      —
      CWE-284
      Referenceadded
      —
      https://github.com/electron/electron/commit/08b9d0a220e267d1a2402a44bdd01a2e9aa320b5
      Referenceadded
      —
      https://github.com/electron/electron/commit/2764e4c35168855f614876051823db4f58a3714a
      Referenceadded
      —
      https://github.com/electron/electron/commit/477dcf7afc6550715f9ec5e6f39ee38e5dd7bf39
      Referenceadded
      —
      https://github.com/electron/electron/commit/c39e3d5687d57434c8d5fe814c5152efd2f631c3
      Referenceadded
      —
      https://github.com/electron/electron/pull/50961
      Referenceadded
      —
      https://github.com/electron/electron/pull/50962
      Referenceadded
      —
      https://github.com/electron/electron/pull/50963
      Referenceadded
      —
      https://github.com/electron/electron/pull/50964
      Referenceadded
      —
      https://github.com/electron/electron/releases/tag/v39.8.8
      Referenceadded
      —
      https://github.com/electron/electron/releases/tag/v40.9.0
      Referenceadded
      —
      https://github.com/electron/electron/releases/tag/v41.2.1
      Referenceadded
      —
      https://github.com/electron/electron/releases/tag/v42.0.0-beta.3
      Referenceadded
      —
      https://github.com/electron/electron/security/advisories/GHSA-p2rr-rvmm-c5fp

      Source identifier: security-advisories@github.com

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