CVE-2026-43941 — electerm
CRITICALCVE-2026-43941 is a critical-severity (CVSS 9.6) remote code execution vulnerability in electerm. No vendor fix is recorded yet; mitigation options are listed below.
Unvalidated shell.openExternal in electerm allows arbitrary protocol execution via terminal link click
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-2026-43941.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-43941 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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
Electerm's terminal hyperlink handler passes any URL clicked in the terminal directly to shell.openExternal without any protocol validation.
When a user connects to a malicious SSH server, the attacker can print a crafted URI in the terminal output. If the victim clicks the link, shell.openExternal executes it using the operating system's default protocol handler.
This can be abused to:
- Trigger dangerous protocol handlers (
ms-msdt:,search-ms:) for code execution - Open local files or network shares (
file://, UNC paths) to leak NTLM hashes or exfiltrate data - Launch any installed application associated with a custom URI scheme
An attacker who controls terminal output (e.g., via a malicious SSH server, compromised remote host, or malicious plugin rendering terminal content) can thus achieve arbitrary code execution or local file access on the victim's machine, requiring only that the victim clicks a displayed link.
Patches
As of electerm v3.7.9, no official patch has been released. Users should monitor the project’s GitHub releases and security page for an update addressing this issue.
Workarounds
Until a patch is available:
- Do not click on any links displayed in terminal sessions connected to untrusted servers.
- If possible, disable hyperlink rendering in electerm's terminal settings.
- Use a terminal multiplexer (e.g., tmux) or a separate terminal application that filters URI schemes when working with untrusted hosts.
- Consider running electerm in a restricted environment (sandbox, AppArmor, SELinux) that limits the spawning of protocol handlers.
Resources
- electerm GitHub Repository
- electerm Security Policy
- Vulnerability details originally reported by external researcher (confirmed on v3.7.9, Win10).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | electerm | all versions | No fix |
Detection & 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.
Remediation status
No patched version of electerm has shipped for CVE-2026-43941 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-43941 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-43941. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-43941 in your dependencies?
O3 Security finds CVE-2026-43941 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.