# CVE-2026-49253: electerm: Path Traversal in Zmodem and Trzsz Download Filename Handling

> A malicious SSH server can exploit path traversal in electerm to write files outside the selected download directory, potentially overwriting sensitive user files.

- **Severity:** High 7.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 19 Aug 2026
- **Updated:** 21 Aug 2026
- **Also known as:** GHSA-38j7-23hf-9mhc

## What is CVE-2026-49253?

CVE-2026-49253 is a high-severity path traversal vulnerability in electerm, published on 19 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

electerm is an open-sourced terminal/ssh/sftp/telnet/serialport/RDP/VNC/Spice/ftp client. Prior to 3.11.11, electerm uses remote-supplied filenames directly with path.join() while receiving Zmodem and Trzsz transfers. In src/app/server/zmodem.js, prepareReceiveFile() joins the filename to the user-selected save path, and in src/app/server/trzsz.js, getUniqueFilePath(), the openSaveFile() callback, and the savedFilePaths mapping construct destinations without sanitization. A malicious SSH server or remote shell can provide a filename containing traversal components such as ../escaped.txt or ../../.bashrc. When the victim accepts the transfer and selects a download directory, electerm can write outside that directory and overwrite files accessible to the desktop user, potentially changing sensitive configuration or impairing availability. This issue is fixed in version 3.11.11.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-49253?

2 open source packages ship an affected version, including electerm.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `electerm` | npm | All versions | 3.11.11 |
| `electerm` | npm | All versions | 3.11.11 |

## How do I fix CVE-2026-49253?

Upgrade electerm to 3.11.11 or later.

## Is CVE-2026-49253 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-49253 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-49253 and fix it if it is affected.

What it is: CVE-2026-49253 is a high-severity path traversal vulnerability in electerm, published on 19 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-49253 exists.

Affected packages and fixed versions:
- electerm (npm): affected all versions; fixed in 3.11.11
- electerm (npm): affected all versions; fixed in 3.11.11

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-49253/ (Markdown: https://insights.sbomify.com/CVE-2026-49253/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-49253
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-49253
- OSV: https://osv.dev/vulnerability/CVE-2026-49253

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-49253/
Summaries are generated and may contain mistakes; the official description above is the record.