CVE-2026-43940 — electerm
HIGHCVE-2026-43940 is a high-severity (CVSS 8.4) Path Traversal vulnerability in electerm. A fix is available for electerm — see the affected versions and patch details below.
electerm: Path traversal in electerm runWidget leads to arbitrary code execution
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-43940.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-43940 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 389,824 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
electermnpmDescription
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
bubblewrapon Linux, AppArmor/SELinux profiles, or Windows sandboxed app execution) to limit the impact of any code execution.
Resources
- electerm GitHub Repository
- electerm Security Policy
- Vulnerability details originally reported by external researcher (PoC confirmed on v3.7.9, Win10).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | electerm | all versions | 3.7.16npm install electerm@3.7.16 |
Affected Products
electermelecterm_projectDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for electerm, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update electerm to 3.7.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-43940 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
Frequently Asked Questions
Is CVE-2026-43940 in your dependencies?
Find it across npm, including transitive dependencies.