CVE-2026-34774: Electron Use-after-free Vulnerability

HIGH
Advisory Identifier: GHSA-532v-xpq5-8h95
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CVSS 8.1
CWE-416
Published
Advisory Summary

CVE-2026-34774 is a HIGH (CVSS 8.1) use-after-free vulnerability (CWE-416: Use After Free) affecting Electron libraries in the npm ecosystem. The issue involves use-after-free in offscreen child window paint callback. Remediation is available by upgrading affected packages to version 39.8.1, 40.7.0, 41.0.0.

CVE-2026-34774 at a Glance

CVE Identifier CVE-2026-34774
GHSA Identifier GHSA-532v-xpq5-8h95
Severity HIGH
CVSS v3.1 Base Score 8.1
CWE Classification CWE-416: Use After Free
Affected Product Electron
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 8.1

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:U/C:H/I:H/A:H).

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

How to Fix CVE-2026-34774

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: 39.8.1 
npm install electron@39.8.1
electron fixed: 40.7.0 
npm install electron@40.7.0
electron fixed: 41.0.0 
npm install electron@41.0.0
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-2026-34774, 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 39.8.1), 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-416: Use After Free, where the product reuses or references memory after it has been freed. at some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. 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 Apps that use offscreen rendering and allow child windows via `window.open()` may be vulnerable to a use-after-free. If the parent offscreen `WebContents` is destroyed while a child window remains open, subsequent paint frames on the child dereference freed memory, which may lead to a crash or memory corruption. Apps are only affected if they use offscreen rendering (`webPreferences.offscreen: true`) and their `setWindowOpenHandler` permits child windows. Apps that do not use offscreen rendering, or that deny child windows, are not affected. ### Workarounds Deny child window creation from offscreen renderers in your `setWindowOpenHandler`, or ensure child windows are closed before the parent is destroyed. ### Fixed Versions * `41.0.0` * `40.7.0` * `39.8.1` ### For more information If there are any questions or comments about this advisory, please email [security@electronjs.org](mailto:security@electronjs.org)

CVE-2026-34774 Affected Electron Versions

3 component(s)
Fixed Versions:
39.8.140.7.041.0.0
Product / Package Ecosystem Affected Versions Fixed Version
electron
npm/electron
npm
< 39.8.1
39.8.1
electron
npm/electron
npm
≥ 40.0.0-alpha.1
< 40.7.0
40.7.0
electron
npm/electron
npm
≥ 41.0.0-alpha.1
< 41.0.0
41.0.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/electron/electron/security/advisories/GHSA-532v-xpq5-8h95
NVD — CVE-2026-34774 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-34774
Electron Source Repository REPOSITORY
https://github.com/electron/electron

Frequently Asked Questions

What is CVE-2026-34774?
CVE-2026-34774 is a security vulnerability in Electron involving Use-after-free in offscreen child window paint callback under CWE-416: Use After Free.
Which Electron versions are affected?
Affected versions include releases prior to 39.8.1, 40.7.0, 41.0.0 across affected packages: electron.
What version fixes CVE-2026-34774?
Upgrading to 39.8.1, 40.7.0, 41.0.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is electron affected?
Yes, electron is affected in releases prior to 39.8.1, 40.7.0, 41.0.0. Upgrade your dependency to 39.8.1, 40.7.0, 41.0.0 or later.
What is the CVSS score of CVE-2026-34774?
CVE-2026-34774 has a CVSS v3.1 base score of 8.1 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-34774?
CVE-2026-34774 is classified under CWE-416: Use After Free (The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.).
How can I check npm dependencies for CVE-2026-34774?
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-532v-xpq5-8h95",
  "modified" : "2026-04-06T23:10:55Z",
  "published" : "2026-04-03T02:42:27Z",
  "aliases" : [ "CVE-2026-34774" ],
  "summary" : "Electron: Use-after-free in offscreen child window paint callback",
  "details" : "### Impact\nApps that use offscreen rendering and allow child windows via `window.open()` may be vulnerable to a use-after-free. If the parent offscreen `WebContents` is destroyed while a child window remains open, subsequent paint frames on the child dereference freed memory, which may lead to a crash or memory corruption.\n\nApps are only affected if they use offscreen rendering (`webPreferences.offscreen: true`) and their `setWindowOpenHandler` permits child windows. Apps that do not use offscreen rendering, or that deny child windows, are not affected.\n\n### Workarounds\nDeny child window creation from offscreen renderers in your `setWindowOpenHandler`, or ensure child windows are closed before the parent is destroyed.\n\n### Fixed Versions\n* `41.0.0`\n* `40.7.0`\n* `39.8.1`\n\n### For more information\nIf there are any questions or comments about this advisory, please email [security@electronjs.org](mailto:security@electronjs.org)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
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      "name" : "electron"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
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      }, {
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      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "electron"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
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      }, {
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      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "electron"
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    "ranges" : [ {
      "type" : "ECOSYSTEM",
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      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/electron/electron/security/advisories/GHSA-532v-xpq5-8h95"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-34774"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/electron/electron"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-416" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-03T02:42:27Z",
    "nvd_published_at" : "2026-04-04T00:16:18Z"
  }
}