CVE-2026-36606: High severity MERCUSYS AC12G (EU) V1 vulnerability

Published Jun 3, 2026

Updated

Mercusys AC12G (EU) V1 router with firmware AC12G(EU)V1200909 encrypts configuration backups with a hardcoded DES key using single DES in ECB mode. An attacker who obtains a backup file can decrypt it to recover all stored credentials including admin password, WiFi PSK, and DDNS credentials.

Affected Software

1 affected component

MERCUSYS AC12G (EU) V1=AC12G(EU)_V1_200909

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade Mercusys AC12G (EU) to a version that resolves this vulnerability.
Fixed in AC12G(EU)_V1_200909

Event History

Jun 3, 2026

CVE Published

via MITRE·12:00 AM

Data Sourced

via MITRE·12:00 AM

Description

Data Sourced

via NVD·06:16 PM

DescriptionSeverityWeakness

Frequently Asked Questions

What is the severity of CVE-2026-36606?

The severity of CVE-2026-36606 is rated high with a score of 7.1 on the CVSS scale.

How does CVE-2026-36606 affect the Mercusys AC12G (EU) V1 router?

CVE-2026-36606 affects the Mercusys AC12G (EU) V1 router by allowing an attacker to decrypt configuration backups encrypted with a hardcoded DES key.

What information can be compromised due to CVE-2026-36606?

An attacker exploiting CVE-2026-36606 can recover stored credentials including the admin password, WiFi PSK, and DDNS credentials.

How do I fix CVE-2026-36606?

To fix CVE-2026-36606, update the router to the latest firmware that addresses the vulnerability.

What encryption method is used in CVE-2026-36606?

CVE-2026-36606 uses single DES in ECB mode for encrypting configuration backups.