MediumCVE-2026-70610

Electron: contextBridge object copy honors prototype setters (CVE-2026-70610)

Published 05.08.2026Last modified 08.10.2026Sources: CVE.org, OSV

What is affected, what to do

Update Electron to version 39.8.9.

Affected: Electron gte 40.0.0-alpha.1, < 40.9.2..*
Electron lt *..39.8.9
Fixed in: Electron 39.8.9

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

0.6 %

EPSS score

Low — model estimates < 1% exploitation likelihood.

Source: FIRST EPSS, percentile 47.0

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: 66.46 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: 0.6 %; 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: 47.0; 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: 05.08.2026
CISA assessment (SSVC): Exploitation: none known · not automatable · Technical impact: partial; Source: CISA Vulnrichment, as of 6 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-1321

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 39.8.9, 40.9.2, 41.2.2, and 42.0.0-beta.4, objects copied across the contextBridge boundary from untrusted content could carry an attacker-influenced prototype, enabling prototype-pollution-style attacks against preload code despite context isolation being enabled. Apps are only affected if their preload code accepts object arguments from untrusted content and reads properties from them without own-property checks, while apps that only accept primitive arguments or validate object arguments are not affected. This issue is fixed in 39.8.9, 40.9.2, 41.2.2, and 42.0.0-beta.4.

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

Affected products

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

Affected products
		Affected versions	Fixed in
electron	electron	`≥ 40.0.0-alpha.1, < 40.9.2` `< 39.8.9`	— `39.8.9`
electronjs	electron	`42.0.0` `41.0.0 – < 41.2.2` `< 39.8.9` `40.0.0 – < 40.9.2`	— `41.2.2` `39.8.9` `40.9.2`

Vendors and products

Weakness classes (CWE)

CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Variant
The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.
Entry at MITRE CWE-1321

References & sources

github.comelectron/electron/security/advisories/GHSA-ff2p-hmqr-hxm4web, x_refsource_CONFIRM
github.comelectron/electron/pull/51083web, x_refsource_MISC
github.comelectron/electron/pull/51084web, x_refsource_MISC
github.comelectron/electron/pull/51085web, x_refsource_MISC
github.comelectron/electron/pull/51086web, x_refsource_MISC
github.comelectron/electron/commit/17d5d26499cd279fab48f5f26527f8edc02a77…web, x_refsource_MISC
github.comelectron/electron/commit/23a6efb714dec80e2cf45d3054d18d701162e4…web, x_refsource_MISC
github.comelectron/electron/commit/4ac50292d552fb510eb778392620c85308770a…web, x_refsource_MISC
github.comelectron/electron/commit/5b699544cbbed51bedb7c60d75c8c42be58257…web, x_refsource_MISC
github.comelectron/electronpackage
github.comelectron/electron/releases/tag/v39.8.9web, x_refsource_MISC
github.comelectron/electron/releases/tag/v40.9.2web, x_refsource_MISC
github.comelectron/electron/releases/tag/v41.2.2web, x_refsource_MISC
github.comelectron/electron/releases/tag/v42.0.0-beta.4web, 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).

08.10.2026Initial analysis by NVDNVD

Newly listed as affected:

HackerOne electron node module (before 39.8.9; 40.0.0 – before 40.9.2; 41.0.0 – before 41.2.2; 9 individual versions)

New references:

and 8 more references

Show 14 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Product configuration	added	—	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: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:: cpe:2.3:a:electronjs:electron::::::node.js:: versions up to (excluding) 39.8.9 cpe:2.3:a:electronjs:electron::::::node.js:: versions from (including) 40.0.0 up to (excluding) 40.9.2 cpe:2.3:a:electronjs:electron::::::node.js:: versions from (including) 41.0.0 up to (excluding) 41.2.2 cpe:2.3:a:electronjs:electron:42.0.0:beta3::::node.js::
Reference type	added	—	GitHub, Inc.: https://github.com/electron/electron/commit/17d5d26499cd279fab48f5f26527f8edc02a7713 Types: Patch
Reference type	added	—	GitHub, Inc.: https://github.com/electron/electron/commit/23a6efb714dec80e2cf45d3054d18d701162e4dd Types: Patch
Reference type	added	—	GitHub, Inc.: https://github.com/electron/electron/commit/4ac50292d552fb510eb778392620c85308770a55 Types: Patch
Reference type	added	—	GitHub, Inc.: https://github.com/electron/electron/commit/5b699544cbbed51bedb7c60d75c8c42be5825737 Types: Patch
Reference type	added	—	GitHub, Inc.: https://github.com/electron/electron/pull/51083 Types: Issue Tracking, Patch
Reference type	added	—	GitHub, Inc.: https://github.com/electron/electron/pull/51084 Types: Issue Tracking, Patch
Reference type	added	—	GitHub, Inc.: https://github.com/electron/electron/pull/51085 Types: Issue Tracking, Patch
Reference type	added	—	GitHub, Inc.: https://github.com/electron/electron/pull/51086 Types: Issue Tracking, Patch
Reference type	added	—	GitHub, Inc.: https://github.com/electron/electron/releases/tag/v39.8.9 Types: Release Notes
Reference type	added	—	GitHub, Inc.: https://github.com/electron/electron/releases/tag/v40.9.2 Types: Release Notes
Reference type	added	—	GitHub, Inc.: https://github.com/electron/electron/releases/tag/v41.2.2 Types: Release Notes
Reference type	added	—	GitHub, Inc.: https://github.com/electron/electron/releases/tag/v42.0.0-beta.4 Types: Release Notes
Reference type	added	—	GitHub, Inc.: https://github.com/electron/electron/security/advisories/GHSA-ff2p-hmqr-hxm4 Types: Mitigation, Vendor Advisory

Source identifier: nvd@nist.gov

06.08.2026Record modifiedCISA ADP

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

Show the original change

Individual changes of this event as published by NVD
Type	Action	Before	After
SSVC assessment	added	—	{"id":"CVE-2026-70610","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-08-06T14:30:58.717300Z"}

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

05.08.2026ReceivedGitHub

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

Weakness type: CWE-1321

Description added or changed

New references:

and 8 more references

Show 17 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Affected versions (publisher)	added	—	electron
Description	added	—	Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.9, 40.9.2, 41.2.2, and 42.0.0-beta.4, objects copied across the contextBridge boundary from untrusted content could carry an attacker-influenced prototype, enabling prototype-pollution-style attacks against preload code despite context isolation being enabled. Apps are only affected if their preload code accepts object arguments from untrusted content and reads properties from them without own-property checks, while apps that only accept primitive arguments or validate object arguments are not affected. This issue is fixed in 39.8.9, 40.9.2, 41.2.2, and 42.0.0-beta.4.
CVSS	added	—	AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
Weakness type (CWE)	added	—	CWE-1321
Reference	added	—	https://github.com/electron/electron/commit/17d5d26499cd279fab48f5f26527f8edc02a7713
Reference	added	—	https://github.com/electron/electron/commit/23a6efb714dec80e2cf45d3054d18d701162e4dd
Reference	added	—	https://github.com/electron/electron/commit/4ac50292d552fb510eb778392620c85308770a55
Reference	added	—	https://github.com/electron/electron/commit/5b699544cbbed51bedb7c60d75c8c42be5825737
Reference	added	—	https://github.com/electron/electron/pull/51083
Reference	added	—	https://github.com/electron/electron/pull/51084
Reference	added	—	https://github.com/electron/electron/pull/51085
Reference	added	—	https://github.com/electron/electron/pull/51086
Reference	added	—	https://github.com/electron/electron/releases/tag/v39.8.9
Reference	added	—	https://github.com/electron/electron/releases/tag/v40.9.2
Reference	added	—	https://github.com/electron/electron/releases/tag/v41.2.2
Reference	added	—	https://github.com/electron/electron/releases/tag/v42.0.0-beta.4
Reference	added	—	https://github.com/electron/electron/security/advisories/GHSA-ff2p-hmqr-hxm4

Source identifier: security-advisories@github.com

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