CVE-2026-34776: Electron Out-of-bounds Read Vulnerability

MODERATE
Advisory Identifier: GHSA-3c8v-cfp5-9885
Share
CVSS 5.3
CWE-125
Published
Advisory Summary

CVE-2026-34776 is a MODERATE (CVSS 5.3) out-of-bounds read vulnerability (CWE-125: Out-of-bounds Read) affecting Electron libraries in the npm ecosystem. The issue involves out-of-bounds read in second-instance ipc on macos and linux. Remediation is available by upgrading affected packages to version 38.8.6, 39.8.1, 40.8.1, 41.0.0.

CVE-2026-34776 at a Glance

CVE Identifier CVE-2026-34776
GHSA Identifier GHSA-3c8v-cfp5-9885
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-125: Out-of-bounds Read
Affected Product Electron
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 5.3

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

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

How to Fix CVE-2026-34776

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: 38.8.6 
npm install electron@38.8.6
electron fixed: 39.8.1 
npm install electron@39.8.1
electron fixed: 40.8.1 
npm install electron@40.8.1
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-2026-34776, 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 38.8.6), 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-125: Out-of-bounds Read, where the product reads data past the end, or before the beginning, of the intended buffer. 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 On macOS and Linux, apps that call `app.requestSingleInstanceLock()` were vulnerable to an out-of-bounds heap read when parsing a crafted second-instance message. Leaked memory could be delivered to the app's `second-instance` event handler. This issue is limited to processes running as the same user as the Electron app. Apps that do not call `app.requestSingleInstanceLock()` are not affected. Windows is not affected by this issue. ### Workarounds There are no app side workarounds, developers must update to a patched version of Electron. ### Fixed Versions * `41.0.0` * `40.8.1` * `39.8.1` * `38.8.6` ### For more information If there are any questions or comments about this advisory, please email [security@electronjs.org](mailto:security@electronjs.org)

CVE-2026-34776 Affected Electron Versions

4 component(s)
Fixed Versions:
38.8.639.8.140.8.141.0.0
Product / Package Ecosystem Affected Versions Fixed Version
electron
npm/electron
npm
< 38.8.6
38.8.6
electron
npm/electron
npm
≥ 39.0.0-alpha.1
< 39.8.1
39.8.1
electron
npm/electron
npm
≥ 40.0.0-alpha.1
< 40.8.1
40.8.1
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-3c8v-cfp5-9885
NVD — CVE-2026-34776 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-34776
Electron Source Repository REPOSITORY
https://github.com/electron/electron

Frequently Asked Questions

What is CVE-2026-34776?
CVE-2026-34776 is a security vulnerability in Electron involving Out-of-bounds read in second-instance IPC on macOS and Linux under CWE-125: Out-of-bounds Read.
Which Electron versions are affected?
Affected versions include releases prior to 38.8.6, 39.8.1, 40.8.1, 41.0.0 across affected packages: electron.
What version fixes CVE-2026-34776?
Upgrading to 38.8.6, 39.8.1, 40.8.1, 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 38.8.6, 39.8.1, 40.8.1, 41.0.0. Upgrade your dependency to 38.8.6, 39.8.1, 40.8.1, 41.0.0 or later.
What is the CVSS score of CVE-2026-34776?
CVE-2026-34776 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:L.
What CWE is associated with CVE-2026-34776?
CVE-2026-34776 is classified under CWE-125: Out-of-bounds Read (The product reads data past the end, or before the beginning, of the intended buffer.).
How can I check npm dependencies for CVE-2026-34776?
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-3c8v-cfp5-9885",
  "modified" : "2026-04-06T23:11:04Z",
  "published" : "2026-04-03T02:43:59Z",
  "aliases" : [ "CVE-2026-34776" ],
  "summary" : "Electron: Out-of-bounds read in second-instance IPC on macOS and Linux",
  "details" : "### Impact\nOn macOS and Linux, apps that call `app.requestSingleInstanceLock()` were vulnerable to an out-of-bounds heap read when parsing a crafted second-instance message. Leaked memory could be delivered to the app's `second-instance` event handler.\n\nThis issue is limited to processes running as the same user as the Electron app.\n\nApps that do not call `app.requestSingleInstanceLock()` are not affected. Windows is not affected by this issue.\n\n### Workarounds\nThere are no app side workarounds, developers must update to a patched version of Electron.\n\n### Fixed Versions\n* `41.0.0`\n* `40.8.1`\n* `39.8.1`\n* `38.8.6`\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:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "electron"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "38.8.6"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "electron"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "39.0.0-alpha.1"
      }, {
        "fixed" : "39.8.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "electron"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "40.0.0-alpha.1"
      }, {
        "fixed" : "40.8.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "electron"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "41.0.0-alpha.1"
      }, {
        "fixed" : "41.0.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/electron/electron/security/advisories/GHSA-3c8v-cfp5-9885"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-34776"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/electron/electron"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-125" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-03T02:43:59Z",
    "nvd_published_at" : "2026-04-04T00:16:18Z"
  }
}