{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 3.11.0"
      },
      "package": {
        "ecosystem": "npm",
        "name": "electerm"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.11.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-49253"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-22"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-02T19:20:20Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Impact\n\nA path traversal vulnerability exists in the Zmodem and Trzsz file download handlers in electerm. When receiving files via Zmodem or Trzsz protocols, electerm uses the remote-supplied filename directly in `path.join()` with the user-selected download directory without sanitization.\n\nA malicious SSH server or remote shell process can send a specially crafted filename such as `../escaped.txt` to escape the user-selected download directory and write files to arbitrary locations on the user\u0027s filesystem, subject to process permissions.\n\n**Attack scenario:**\n1. User connects to a malicious SSH server\n2. Attacker initiates a Zmodem or Trzsz file transfer\n3. Attacker supplies a traversal filename (e.g., `../../.bashrc`, `../escaped.txt`)\n4. User accepts the transfer and selects a download directory\n5. File is written outside the selected directory, potentially overwriting sensitive files\n\n**Affected components:**\n- `src/app/server/zmodem.js` - `prepareReceiveFile()` at line 736\n- `src/app/server/trzsz.js` - `getUniqueFilePath()` at line 559, `openSaveFile()` callback, and `savedFilePaths` mapping\n\n### Patches\n\n- https://github.com/electerm/electerm/commit/fde153d677a170c5816368f6586647f3af4ef284\n\n### Workarounds\n\n\nIf upgrading is not immediately possible, users can mitigate this vulnerability by:\n1. Only connecting to trusted SSH servers\n2. Rejecting or canceling any incoming Zmodem or Trzsz file transfers from untrusted sources\n3. Avoiding the use of Zmodem (`sz`/`rz`) and Trzsz (`trz`/`tsz`) commands on untrusted servers",
  "id": "GHSA-38j7-23hf-9mhc",
  "modified": "2026-07-02T19:20:20Z",
  "published": "2026-07-02T19:20:20Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/electerm/electerm/security/advisories/GHSA-38j7-23hf-9mhc"
    },
    {
      "type": "WEB",
      "url": "https://github.com/electerm/electerm/commit/fde153d677a170c5816368f6586647f3af4ef284"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/electerm/electerm"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "electerm has Path Traversal in Zmodem and Trzsz Download Filename Handling"
}