Path Traversal in electerm (CVE-2026-49253)
Summary
Path traversal in electerm (CVE-2026-49253). Data can be tampered with by attackers. Exploitable via savedFilePaths. Mitigation: upgrade to 3.11.11 or later.
Original description
The description as published by the source.
Impact
A 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.
A 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's filesystem, subject to process permissions.
Attack scenario:
- User connects to a malicious SSH server
- Attacker initiates a Zmodem or Trzsz file transfer
- Attacker supplies a traversal filename (e.g.,
../../.bashrc,../escaped.txt) - User accepts the transfer and selects a download directory
- File is written outside the selected directory, potentially overwriting sensitive files
Affected components:
src/app/server/zmodem.js-prepareReceiveFile()at line 736src/app/server/trzsz.js-getUniqueFilePath()at line 559,openSaveFile()callback, andsavedFilePathsmapping
Patches
Workarounds
If upgrading is not immediately possible, users can mitigate this vulnerability by:
- Only connecting to trusted SSH servers
- Rejecting or canceling any incoming Zmodem or Trzsz file transfers from untrusted sources
- Avoiding the use of Zmodem (
sz/rz) a…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-49253 has been found in electerm.
Attackers can target a specific entry point like savedFilePaths over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 7.1/10.
What to do: upgrade electerm to 3.11.11 or later.
If unsure, ask your IT team or search "electerm CVE-2026-49253" on the vendor's site.
CVE-2026-49253 (electerm) — CWE-22 / CVSS v3 7.1
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: savedFilePaths / trz / tsz
Patched: 3.11.11 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Path traversal (CWE-22) exists in electerm. Attackers reach the vulnerable code path via savedFilePaths without authentication.
Check the vendor advisory for the affected versions of electerm. Attack surface: savedFilePaths / trz / tsz.
Severity: High (CVSS 7.1/10). Data can be tampered with by attackers.
Update to 3.11.11.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'electerm' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'electerm' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
electermを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade electerm to 3.11.11ステージング環境で 3.11.11 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- package github.com
- web github.com
- web security-advisories@github.com
- web github.com
- web security-advisories@github.com