CVE-2026-70603

Unintended file opening via embedded null byte

Published Aug 5, 2026 · Updated Aug 5, 2026

Path validation bypass in affected Electron releases allows local users to open unintended files through shell.openPath(). The shell.openPath() binding accepts paths with embedded null bytes after string-only checks, so the file opened can differ from the path that passed validation. Exploitation requires an application to pass an untrusted path to shell.openPath(), rely only on string validation, and involve user interaction; Node filesystem checks prevent the mismatch.

CVSS severity6.0
Medium
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path validation bypass in affected Electron releases allows local users to open unintended files through shell.openPath(). The shell.openPath() binding accepts paths with embedded null bytes after string-only checks, so the file opened can differ from the path that passed validation. Exploitation requires an application to pass an untrusted path to shell.openPath(), rely only on string validation, and involve user interaction; Node filesystem checks prevent the mismatch.

The record

CVE
CVE-2026-70603
Published
Aug 5, 2026
Updated
Aug 5, 2026
Vendor
Electron
Product
Electron
Classifications
CWE-158, CWE-20, T1204
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 39.8.6
  2. Affected versionversion=>= 40.0.0-alpha.1, < 40.9.0
  3. Affected versionversion=>= 41.0.0-alpha.1, < 41.1.1
  4. Affected versionversion=>= 42.0.0-alpha.1, < 42.0.0-beta.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Electron · Electronversion=< 39.8.6; version=>= 40.0.0-alpha.1, < 40.9.0; version=>= 41.0.0-alpha.1, < 41.1.1; version=>= 42.0.0-alpha.1, < 42.0.0-beta.1

Published CVSS scores

6.0GitHub, Inc.CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-158Improper Neutralization of Null Byte or NUL Character
CWE-20Improper Input Validation
T1204User Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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