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Electerm runWidget has a path traversal that leads to arbitrary code execution

Critical severity GitHub Reviewed Published May 4, 2026 in electerm/electerm • Updated May 8, 2026

Package

npm electerm (npm)

Affected versions

< 3.7.16

Patched versions

3.7.16

Description

Impact

The runWidget function in src/app/widgets/load-widget.js constructs a file path by directly concatenating user‑supplied widget identifiers without any sanitisation:

const file = `widget-${widgetId}.js`
const widget = require(path.join(__dirname, file))

Because runWidget is exposed to the renderer process via an asynchronous IPC handler with no input validation, an attacker who achieves JavaScript execution inside the renderer (for example, through a malicious plugin or a cross‑site scripting flaw in the built‑in webview) can abuse a path traversal (../) to load and execute an arbitrary JavaScript file anywhere on the victim’s filesystem. This gives the attacker local code execution with the full privileges of the electerm process, leading to complete system compromise.

Patches

Fixed in version >= 3.7.16

Workarounds

Until a patch is released:

  • Do not install or run untrusted plugins.
  • Avoid loading arbitrary web content inside electerm’s embedded webview (for example, disable any features that fetch and display remote HTML).
  • Run electerm in a sandboxed environment (e.g., with bubblewrap on Linux, AppArmor/SELinux profiles, or Windows sandboxed app execution) to limit the impact of any code execution.

Resources

References

@zxdong262 zxdong262 published to electerm/electerm May 4, 2026
Published by the National Vulnerability Database May 8, 2026
Published to the GitHub Advisory Database May 8, 2026
Reviewed May 8, 2026
Last updated May 8, 2026

Severity

Critical

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
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
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:N/AC:L/PR:N/UI:N/S:U/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.
(6th percentile)

Weaknesses

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. Learn more on MITRE.

Inclusion of Functionality from Untrusted Control Sphere

The product imports, requires, or includes executable functionality (such as a library) from a source that is outside of the intended control sphere. Learn more on MITRE.

CVE ID

CVE-2026-43940

GHSA ID

GHSA-f77v-9vpc-6pjm

Source code

Credits

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