---
id: "CVE-2026-121618"
kind: "vulnerability"
aliases: ["CVE-2026-121618"]
title: "Linksys E5600 router: factory test CGI leaks information remotely"
severity: "medium"
cvss: 5.5
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["e5600", "firmware", "home-router", "infrastructure", "linksys"]
not_affected_if: ["cgi-not-exposed", "different-firmware"]
published_at: "2026-11-04T03:17:15+00:00"
first_seen_at: "2026-11-04T03:46:40+00:00"
updated_at: "2026-11-04T03:47:15+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121618", "first_seen_at": "2026-11-04T03:46:40+00:00"}]
---

# Linksys E5600 router: factory test CGI leaks information remotely

A weakness in the Factory Quality Control CGI script (/cgi-bin/fqc.cgi) of Linksys E5600 firmware 1.1.0.26 lets a remote attacker disclose information. A public exploit exists, and the vendor did not respond to the disclosure.

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

## How to check

- Check the firmware version on the router's admin page and look for `1.1.0.26`
- Test whether `/cgi-bin/fqc.cgi` responds on the device from the network

## Timeline

- 2026-11-04T03:46:40+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121618

## From the sources

A weakness has been identified in Linksys E5600 1.1.0.26. This affects an unknown part of the file /cgi-bin/fqc.cgi of the component Factory Quality Control. This manipulation causes information disclosure. Remote exploitation of the attack is possible. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way. This vulnerability only affects products that are no longer supported by the maintainer.

---

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