CVE-2026-34765
Electronjs Electron ≤ 39.8.4
Raw vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:LSummary
CVE-2026-34765 is a medium-severity Exposure of Resource to Wrong Sphere (CWE-668) vulnerability in Electronjs Electron. Its CVSS base score is 6.0 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Cloud Instance Metadata API (T1552.005); ranked at the 22th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-34765 is a vulnerability in the Electron framework, which enables cross-platform desktop applications using JavaScript, HTML, and CSS. In versions prior to 39.8.5, 40.8.5, 41.1.0, and 42.0.0-alpha.5, Electron fails to properly scope named-window lookups to the opener's browsing context group when a renderer calls window.open() with a target name. This allows a renderer to navigate an existing child window opened by a different, unrelated renderer if both use the same target name. Affected applications are those that open multiple top-level windows with differing trust levels and use setWindowOpenHandler to grant child windows elevated webPreferences, such as privileged preload scripts; applications using a single top-level window or not elevating child privileges remain unaffected. The issue is classified under CWE-668 with a CVSS v3.1 base score of 6.0 (AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L).
Exploitation requires an attacker with low privileges (PR:L) in a renderer process, such as an authenticated but untrusted renderer, to target an existing child window created by a higher-trust renderer using the same window name. By navigating that child window, the attacker's content can inherit the more permissive webPreferences configured via setWindowOpenHandler's overrideBrowserWindowOptions. This enables privilege escalation within the application's context. If the application additionally sets nodeIntegration: true or sandbox: false on child windows—contrary to security best practices—the attacker may achieve arbitrary code execution. The attack is network-vector (AV:N) but high complexity (AC:H), with no user interaction needed (UI:N) and changed scope (S:C) leading to low impacts on confidentiality, integrity, and availability.
The Electron security advisory at https://github.com/electron/electron/security/advisories/GHSA-f3pv-wv63-48x8 details the fix implemented in versions 39.8.5, 40.8.5, 41.1.0, and 42.0.0-alpha.5, which correctly scopes window lookups to the opener's browsing context group. Security practitioners should upgrade affected Electron instances immediately and audit applications for multi-window setups with varying trust levels and custom setWindowOpenHandler configurations to prevent exposure.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-19949
Vulnerability Data
Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.5, 40.8.5, 41.1.0, and 42.0.0-alpha.5, when a renderer calls window.open() with a target name, Electron did not correctly scope the named-window lookup to the…
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opener's browsing context group. A renderer could navigate an existing child window that was opened by a different, unrelated renderer if both used the same target name. If that existing child was created with more permissive webPreferences (via setWindowOpenHandler's overrideBrowserWindowOptions), content loaded by the second renderer inherits those permissions. Apps are only affected if they open multiple top-level windows with differing trust levels and use setWindowOpenHandler to grant child windows elevated webPreferences such as a privileged preload script. Apps that do not elevate child window privileges, or that use a single top-level window, are not affected. Apps that additionally grant nodeIntegration: true or sandbox: false to child windows (contrary to the security recommendations) may be exposed to arbitrary code execution. This vulnerability is fixed in 39.8.5, 40.8.5, 41.1.0, and 42.0.0-alpha.5.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 8 hardening rules · 7 OS baselines
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Mitigating Controls (NIST 800-53 r5) AI
Access enforcement directly stops resources from being reachable by actors outside the intended control sphere.
Information flow enforcement structurally prevents unintended cross-sphere data or resource exposure.
Least privilege reduces the set of actors that can reach a resource, limiting wrong-sphere exposure.
Security attributes enable correct sphere assignment and subsequent enforcement decisions.
Boundary protection at interfaces prevents resources from being exposed outside authorized spheres.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Enforcing least-privilege authorizations directly prevents resources from being exposed outside their intended control sphere.
Network segmentation and unauthorized-access protections reduce the chance of resources being reachable by the wrong sphere.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Placing systems of differing trust levels into separate domains prevents resources from being placed in a sphere where they are reachable by unintended actors.
Requiring owners to manage the full asset life cycle and remove assets from the inventory upon secure disposal helps prevent resources from being inadvertently exposed outside their intended security sphere.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (2 rules)
- V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-668
- V-248823 OL 8 must not have the telnet-server package installed. prevents CWE-668
RHEL 7 (1 rule)
- V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. prevents CWE-668
Windows 10 (1 rule)
- V-220967 The Debug programs user right must only be assigned to the Administrators group. prevents CWE-668
Windows 11 (1 rule)
- V-253490 The "Debug programs" user right must only be assigned to the Administrators group. prevents CWE-668
Windows Server 2016 (1 rule)
- V-225079 The Debug programs user right must only be assigned to the Administrators group. prevents CWE-668
Windows Server 2019 (1 rule)
- V-205757 Windows Server 2019 Debug programs: user right must only be assigned to the Administrators group. prevents CWE-668
Windows Server 2022 (1 rule)
- V-254500 Windows Server 2022 debug programs user right must only be assigned to the Administrators group. prevents CWE-668