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Electron: Sandboxed preload code cache can be poisoned by a compromised renderer

High severity GitHub Reviewed Published Aug 29, 2026 in electron/electron • Updated Sep 29, 2026

Package

npm electron (npm)

Affected versions

>= 42.3.3, < 42.10.0
>= 43.0.0-beta.1, < 43.5.0
>= 44.0.0-alpha.1, < 44.0.0-beta.6

Patched versions

42.10.0
43.5.0
44.0.0-beta.6

Description

Impact

The cache Electron keeps for sandboxed preload scripts did not verify that a cached entry matched the preload it was served for. A compromised renderer could use this to run its own code in the preload context on a later load.

Apps are only affected if they load untrusted content. Apps that do not load untrusted content are not affected.

Workarounds

There are no app side workarounds, you must update to a patched version of Electron.

Fixed Versions

  • 44.0.0-beta.6
  • 43.5.0
  • 42.10.0

For more information

If you have any questions or comments about this advisory, email us at security@electronjs.org

References

@MarshallOfSound MarshallOfSound published to electron/electron Aug 29, 2026
Published to the GitHub Advisory Database Sep 29, 2026
Reviewed Sep 29, 2026
Last updated Sep 29, 2026

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(1st percentile)

Weaknesses

Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. Learn more on MITRE.

Insufficient Verification of Data Authenticity

The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data. Learn more on MITRE.

CVE ID

CVE-2026-102677

GHSA ID

GHSA-qmv3-fv6v-rmhq

Source code

Credits

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