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.
- 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
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
Which versions are affected by CVE-2026-49253?
2 open source packages ship an affected version, including electerm.
| Package | 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.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-49253 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-49253 exists.
Sources
Also known as GHSA-38j7-23hf-9mhc.