---
title: "CVE-2026-43940: Electerm runWidget has a path traversal that leads to arbitrary code execution"
url: https://erroneo.us/security/cve/CVE-2026-43940/
description: "CVE-2026-43940 (electerm (npm)): electerm is an open-sourced terminal/ssh/sftp/telnet/serialport/RDP/VNC/Spice/ftp client. Prior to version 3.7.16, the…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-05-08
date_modified: 2026-05-08
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-43940"
kev: false
cvss: 8.4
epss: 0.00223
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-43940: Electerm runWidget has a path traversal that leads to arbitrary code execution

**Signal:** Normal patch cycle. No exploitation signal; fix it in your next routine update if you are affected. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.2% , percentile 12: FIRST’s model estimates a 0.2% chance of exploitation activity in the next 30 days, higher than 12% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs local access needed. Lower urgency for most teams unless an attacker could already run code on the machine.
- Only applies if your dependency tree includes electerm (npm) < 3.7.16, fixed in 3.7.16 . Check your lockfile, including transitive dependencies.

## What it is

electerm is an open-sourced terminal/ssh/sftp/telnet/serialport/RDP/VNC/Spice/ftp client. Prior to version 3.7.16, the runWidget function in src/app/widgets/load-widget.js constructs a file path by directly concatenating user‑supplied widget identifiers without any sanitisation. 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. This issue has been patched in version 3.7.16.

## Affected packages

- npm `electerm` < 3.7.16 → fixed: 3.7.16

## Affected products (CVE record)

- electerm electerm: < 3.7.16

## Severity

- GitHub_M CVSS 3.1: 8.4 `CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.22% probability of exploitation activity in the next 30 days; percentile 12.

## Sources

- [GitHub Advisory GHSA-f77v-9vpc-6pjm](https://github.com/advisories/GHSA-f77v-9vpc-6pjm)
- [CVE.org record CVE-2026-43940](https://www.cve.org/CVERecord?id=CVE-2026-43940)
- [NVD entry CVE-2026-43940](https://nvd.nist.gov/vuln/detail/CVE-2026-43940)
- [github.com](https://github.com/electerm/electerm/security/advisories/GHSA-f77v-9vpc-6pjm)
- [github.com](https://github.com/electerm/electerm/releases/tag/v3.7.16)

---
Source page: https://erroneo.us/security/cve/CVE-2026-43940/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt