Classic Buffer OverflowWeakness · CWE-120

CVE-2026-54257

CRITICAL · 9.3 CVSS v4.0 Published 2026-06-23
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. From 42.3.1 until 42.3.3, Buffer performs incorrect byte length calculations resulting in heap buffer under/overflow. Most apps will crash and some may perform incorrect buffer allocations in the Node.js Buffer API resulting in unexpected truncation or allocation. This vulnerability is fixed in 42.3.3.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Electron versions 42.3.1 through 42.3.3 contain a heap buffer underflow/overflow vulnerability in the Buffer implementation due to incorrect byte length calculations. This flaw in the Node.js Buffer API can cause application crashes, incorrect buffer allocations, unexpected truncation, or memory corruption.

MitigationUpgrade Electron to version 42.3.3 or later to resolve the Buffer byte length calculation vulnerability. Test all Buffer API usage thoroughly after the update.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Determine your Electron version
    Run `electron --version` from your terminal, or in your running Electron app execute `console.log(process.versions.electron)`
    Affected if The version is 42.3.1, 42.3.2, or 42.3.3 exactly
  2. Confirm Node.js runtime version
    Run `node --version` or in the app execute `console.log(process.versions.node)`
    Affected if Node.js version is bundled with the affected Electron versions (combined check helps confirm the build)
  3. Identify Buffer API usage
    Search your codebase for Buffer constructor calls such as `new Buffer()`, `Buffer.alloc()`, `Buffer.from()`, or any buffer manipulation methods
    Affected if Your application uses Node.js Buffer API operations and runs the affected Electron version
  4. Check for external input-driven buffer operations
    Review code paths where external input (file contents, network data, user input) flows into Buffer creation or manipulation functions
    Affected if External data influences buffer size or content and the affected Electron version is in use

You are affected if your installed Electron version is exactly 42.3.1, 42.3.2, or 42.3.3 and your application uses the Node.js Buffer API with data that could trigger incorrect length calculations.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Electron to version 42.3.3 or later to resolve the Buffer byte length calculation vulnerability. Test all Buffer API usage thoroughly after the update.

Recommended fix High confidence

Electron 42.3.3 or later

  1. 1. Identify the current Electron version in your application by checking package.json or running `npm list electron`
  2. 2. If your Electron version is 42.3.1 or 42.3.2, update your package.json to specify Electron version 42.3.3 or later
  3. 3. Run `npm install` or `npm update` to install the fixed version
  4. 4. Rebuild and test your application thoroughly to ensure compatibility with the update
  5. 5. Redeploy the application to all environments
Caveat Review release notes for any breaking changes between your current version and 42.3.3; minor version updates in Electron may include API changes or deprecations

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
Get help mitigating

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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-54257 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data