---
id: "CVE-2026-12489"
kind: "vulnerability"
aliases: ["CVE-2026-12489"]
title: "Zyxel EX3501-T0 firmware: authenticated users can escalate privileges via login_privilege"
severity: "medium"
cvss: 6.5
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["firmware", "infrastructure", "network-gear", "zyxel"]
not_affected_if: ["newer-firmware", "other-zyxel-models"]
published_at: "2026-10-20T03:17:15+00:00"
first_seen_at: "2026-10-23T21:57:19+00:00"
updated_at: "2026-10-25T03:55:42+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-12489", "first_seen_at": "2026-10-23T21:57:19+00:00"}]
---

# Zyxel EX3501-T0 firmware: authenticated users can escalate privileges via login_privilege

An incorrect authorization flaw in the Data Access Layer of Zyxel EX3501-T0 firmware up to 5.44(ACHR.6)C0 lets a logged-in user change the login_privilege data. That lets the attacker raise their own privileges on the device.

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

## How to check

- Check the installed firmware version on the device (unknown exact command or menu path in the sources)
- Compare the version against `5.44(ACHR.6)C0` and earlier builds listed as affected

## Fix

- Update the EX3501-T0 firmware to a version newer than `5.44(ACHR.6)C0` (the fixed version is unknown from the sources)

## Timeline

- 2026-10-23T21:57:19+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-12489

## From the sources

An incorrect authorization vulnerability in the Data Access Layer (DAL) of Zyxel EX3501-T0 firmware versions through 5.44(ACHR.6)C0 could allow an authenticated attacker to escalate privileges by modifying the login_privilege data on an affected device.

---

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