Summary
Electerm has an unvalidated shell.openExternal that allows arbitrary protocol execution via terminal link click
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).
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.
Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites. Typical impact: phishing and credential harvesting via a trusted domain.
CVE-2026-43941 has a CVSS score of 8.8 (High). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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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.
Frequently Asked Questions
- What is CVE-2026-43941? CVE-2026-43941 is a high-severity open redirect vulnerability in electerm (npm), affecting versions <= 3.8.15. No fixed version is listed yet. Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites.
- How severe is CVE-2026-43941? CVE-2026-43941 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of electerm are affected by CVE-2026-43941? electerm (npm) versions <= 3.8.15 is affected.
- Is there a fix for CVE-2026-43941? No fixed version is listed for CVE-2026-43941 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2026-43941 exploitable, and should I be worried? Whether CVE-2026-43941 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-43941 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-43941? No fixed version is listed yet. In the interim: Validate redirect destinations against an allowlist of permitted URLs or paths. Reject destinations that include an unexpected authority component.