CVE-2026-49255 is a high-severity (CVSS 8.8) OS Command Injection vulnerability in electerm. A fix is available for electerm — see the affected versions and patch details below.
electerm: Command Injection in File System Operations (rmrf, mv, cp)
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-2026-49255.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
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
A command injection vulnerability exists in electerm's file system operations (rmrf, mv, cp) in src/app/lib/fs.js. These functions construct shell commands by interpolating file paths directly into command strings without escaping shell metacharacters.
Vulnerable functions:
rmrf()- Usesrm -rf "${path}"(double quotes, vulnerable to"injection)mv()- Usesmv '${from}' '${to}'(single quotes, vulnerable to'injection)cp()- Usescp -r "${from}" "${to}"(double quotes, vulnerable to"injection)
Attack scenario:
- Attacker controls a malicious SSH/SFTP server
- Server lists files with shell metacharacters in names (e.g.,
file"$(touch /tmp/pwned)") - Victim connects to the server and performs file operations (remote-to-local transfer, rename on conflict, etc.)
- The malicious filename is passed to
rmrf(),mv(), orcp()without sanitization - Shell metacharacters break out of the quoted argument and execute arbitrary commands
Impact includes:
- Arbitrary command execution as the electerm desktop user
- Data exfiltration, malware installation, or system compromise
- Both POSIX (bash) and Windows (PowerShell) platforms are affected
Patches
Workarounds
If upgrading is not immediately possible, users can mitigate this vulnerability by:
- Only connecting to trusted SSH/SFTP servers
- Avoiding remote-to-local file transfers from untrusted sources
- Not using the "rename on conflict" option when downloading folders from untrusted servers
- Manually verifying filenames before performing file operations
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | electerm | all versions | 3.11.11npm install electerm@3.11.11 |
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.
Fix
Update electerm to 3.11.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-49255 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
Frequently Asked Questions
Is CVE-2026-49255 in your dependencies?
Find it across npm, including transitive dependencies.