CVE-2026-70610: Electron ContextBridge Object Copy Honors Prototype Vulnerability

MODERATE
Advisory Identifier: GHSA-ff2p-hmqr-hxm4
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CVSS 5.4
CWE-1321
Published
Advisory Summary

CVE-2026-70610 is a MODERATE (CVSS 5.4) contextbridge object copy honors prototype vulnerability (CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')) affecting Electron libraries in the npm ecosystem. The issue involves contextbridge object copy honors prototype setters. Remediation is available by upgrading affected packages to version 39.8.9, 40.9.2, 41.2.2, 42.0.0-beta.4.

CVE-2026-70610 at a Glance

CVE Identifier CVE-2026-70610
GHSA Identifier GHSA-ff2p-hmqr-hxm4
Severity MODERATE
CVSS v3.1 Base Score 5.4
CWE Classification CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Affected Product Electron
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 5.4

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-70610

To remediate this vulnerability, upgrade all affected Electron dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

electron fixed: 39.8.9 
npm install electron@39.8.9
electron fixed: 40.9.2 
npm install electron@40.9.2
electron fixed: 41.2.2 
npm install electron@41.2.2
electron fixed: 42.0.0-beta.4 
npm install electron@42.0.0-beta.4
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls electron

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-70610, inspect your project dependencies using npm:

npm ls electron

Analyze the terminal output to locate any version of Electron in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 39.8.9), your application is affected.

Note: The npm ls electron command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution'), where 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. In Electron, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact 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. Apps that only accept primitive arguments, or that validate object arguments, are not affected. ### Workarounds Validate objects received from untrusted content with own-property checks (`Object.hasOwn`), or copy them onto a null-prototype object before use. ### Fixed Versions * `42.0.0-beta.4` * `41.2.2` * `40.9.2` * `39.8.9` ### For more information If you have any questions or comments about this advisory, email Electron at [security@electronjs.org](mailto:security@electronjs.org)

CVE-2026-70610 Affected Electron Versions

4 component(s)
Fixed Versions:
39.8.940.9.241.2.242.0.0-beta.4
Product / Package Ecosystem Affected Versions Fixed Version
electron
npm/electron
npm
< 39.8.9
39.8.9
electron
npm/electron
npm
≥ 40.0.0-alpha.1
< 40.9.2
40.9.2
electron
npm/electron
npm
≥ 41.0.0-alpha.1
< 41.2.2
41.2.2
electron
npm/electron
npm
≥ 42.0.0-alpha.1
< 42.0.0-beta.4
42.0.0-beta.4

References

GitHub Advisory / Wiki ADVISORY
https://github.com/electron/electron/security/advisories/GHSA-ff2p-hmqr-hxm4
Electron Source Repository REPOSITORY
https://github.com/electron/electron/pull/51083
Electron Source Repository REPOSITORY
https://github.com/electron/electron/pull/51084
Electron Source Repository REPOSITORY
https://github.com/electron/electron/pull/51085
Electron Source Repository REPOSITORY
https://github.com/electron/electron/pull/51086
Security Fix Commit FIX COMMIT
https://github.com/electron/electron/commit/17d5d26499cd279fab48f5f26527f8edc02a7713
Security Fix Commit FIX COMMIT
https://github.com/electron/electron/commit/23a6efb714dec80e2cf45d3054d18d701162e4dd
Security Fix Commit FIX COMMIT
https://github.com/electron/electron/commit/4ac50292d552fb510eb778392620c85308770a55
Security Fix Commit FIX COMMIT
https://github.com/electron/electron/commit/5b699544cbbed51bedb7c60d75c8c42be5825737
Electron Source Repository REPOSITORY
https://github.com/electron/electron
Electron Release RELEASE
https://github.com/electron/electron/releases/tag/v39.8.9
Electron Release RELEASE
https://github.com/electron/electron/releases/tag/v40.9.2
Electron Release RELEASE
https://github.com/electron/electron/releases/tag/v41.2.2
Electron Release RELEASE
https://github.com/electron/electron/releases/tag/v42.0.0-beta.4

Frequently Asked Questions

What is CVE-2026-70610?
CVE-2026-70610 is a security vulnerability in Electron involving contextBridge object copy honors prototype setters under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution').
Which Electron versions are affected?
Affected versions include releases prior to 39.8.9, 40.9.2, 41.2.2, 42.0.0-beta.4 across affected packages: electron.
What version fixes CVE-2026-70610?
Upgrading to 39.8.9, 40.9.2, 41.2.2, 42.0.0-beta.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is electron affected?
Yes, electron is affected in releases prior to 39.8.9, 40.9.2, 41.2.2, 42.0.0-beta.4. Upgrade your dependency to 39.8.9, 40.9.2, 41.2.2, 42.0.0-beta.4 or later.
What is the CVSS score of CVE-2026-70610?
CVE-2026-70610 has a CVSS v3.1 base score of 5.4 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2026-70610?
CVE-2026-70610 is classified under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') (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.).
How can I check npm dependencies for CVE-2026-70610?
Run the dependency tree command: 'npm ls electron'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-ff2p-hmqr-hxm4",
  "modified" : "2026-08-05T17:41:21Z",
  "published" : "2026-08-05T17:41:20Z",
  "aliases" : [ "CVE-2026-70610" ],
  "summary" : "Electron: contextBridge object copy honors prototype setters",
  "details" : "### Impact\nObjects 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.\n\nApps are only affected if their preload code accepts object arguments from untrusted content and reads properties from them without own-property checks. Apps that only accept primitive arguments, or that validate object arguments, are not affected.\n\n### Workarounds\nValidate objects received from untrusted content with own-property checks (`Object.hasOwn`), or copy them onto a null-prototype object before use.\n\n### Fixed Versions\n* `42.0.0-beta.4`\n* `41.2.2`\n* `40.9.2`\n* `39.8.9`\n\n### For more information\nIf you have any questions or comments about this advisory, email Electron at [security@electronjs.org](mailto:security@electronjs.org)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N"
  } ],
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    },
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    } ]
  }, {
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    } ]
  }, {
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    "ranges" : [ {
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      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/electron/electron/security/advisories/GHSA-ff2p-hmqr-hxm4"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/electron/electron/pull/51083"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/electron/electron/pull/51084"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/electron/electron/pull/51085"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/electron/electron/pull/51086"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/electron/electron/commit/17d5d26499cd279fab48f5f26527f8edc02a7713"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/electron/electron/commit/23a6efb714dec80e2cf45d3054d18d701162e4dd"
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    "url" : "https://github.com/electron/electron/commit/4ac50292d552fb510eb778392620c85308770a55"
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    "url" : "https://github.com/electron/electron/commit/5b699544cbbed51bedb7c60d75c8c42be5825737"
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  }, {
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    "url" : "https://github.com/electron/electron/releases/tag/v39.8.9"
  }, {
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  }, {
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  }, {
    "type" : "WEB",
    "url" : "https://github.com/electron/electron/releases/tag/v42.0.0-beta.4"
  } ],
  "database_specific" : {
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    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-05T17:41:20Z",
    "nvd_published_at" : null
  }
}