---
id: "CVE-2026-118238"
kind: "vulnerability"
aliases: ["CVE-2026-118238"]
title: "Tenda W18E router: command injection via diagnose packet-capture feature"
severity: "critical"
cvss: null
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: [{"name": "Tenda W18E", "fixed": [], "affected": "16.01.0.20 (per aggregators, unconfirmed)", "ecosystem": "vendor"}]
ecosystems: []
tags: ["infrastructure", "routers", "self-hosted", "tenda", "w18e"]
not_affected_if: ["management-interface-not-reachable", "not-w18e-hardware"]
published_at: "2026-10-30T16:17:41+00:00"
first_seen_at: "2026-10-30T16:31:25+00:00"
updated_at: "2026-10-30T16:33:49+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118238", "first_seen_at": "2026-10-30T16:31:25+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-10-30T16:33:49+00:00"}]
---

# Tenda W18E router: command injection via diagnose packet-capture feature

The Tenda W18E router web management server passes unvalidated JSON fields into a tcpdump shell command. An attacker who can reach the admin interface can run arbitrary OS commands as root.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Tenda W18E affected 16.01.0.20 (per aggregators, unconfirmed) fixed ?

## How to check

- In the W18E admin UI (System status), read the firmware version; V16.01.0.20 is the reported affected build, and other builds are unconfirmed.
- Check whether the admin web interface is reachable from the internet or untrusted LAN segments (remote management / port forwards).
- Any W18E still in factory-reset state with no admin password set can be treated as unauthenticated-exploitable; set an admin password now.

## Timeline

- 2026-10-30T16:31:25+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-118238
- 2026-10-30T16:33:49+00:00 analyst — No vendor advisory found; Tenda page not located. NVD text: injection in protocol/targetDevice JSON fields into tcpdump, root; unauthenticated only in factory-reset state, else needs login. Aggregators (OffSeq, HOL) list affected V16.01.0.20, no fix; unconfirmed by vendor. Researcher JiuZero blog (2026-09-19, W18E V2.0 httpd, PoC suite) is password-locked, so unread. No exploitation reports. Nothing marked verified.

## Documents

- [advisory] NVD CVE-2026-118238 https://nvd.nist.gov/vuln/detail/CVE-2026-118238
- [describes] JiuZero: Tenda W18E V2.0 httpd unauthenticated command injection (body password-locked) https://jiuzero.github.io/2026/09/19/Tenda-W18E-V2.0-httpd-Unauthenticated-OS-Command-Injection-in-the-Packet-Capture-Diagnostic-Feature-Root-RCE/
- [mentions] OffSeq Threat Radar: CVE-2026-118238 (affected 16.01.0.20, no fix) https://radar.offseq.com/threat/cve-2026-118238-cwe-78-os-command-injection-in-tenda-w18e-d95143eccf2fd1cc

## From the sources

The Tenda W18E web management server is vulnerable to OS command injection via the "diagnose" packet-capture feature due to improper validation of JSON fields. An authenticated user can inject shell metacharacters into the protocol or targetDevice fields, which are later concatenated into a tcpdump command and executed with root privileges. This vulnerability can be exploited without authentication if the device is in a factory-reset state.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_