Security Flaw in Mercusys AC12G Router with Insecure DDNS Credential Transmission
CVE-2026-36610

5.9MEDIUM

Key Information:

Vendor

Mercusys

Status
AC12G
Vendor
CVE Published:
3 June 2026

What is CVE-2026-36610?

The Mercusys AC12G (EU) V1 router, running firmware version AC12G(EU)_V1_200909, has a significant security issue whereby it transmits Dynamic DNS (DDNS) credentials in plaintext over HTTP, utilizing only Base64 encoding for the data. This absence of proper encryption means the credentials can be intercepted by malicious actors performing man-in-the-middle attacks, exposing the device to unauthorized access. The lack of TLS implementation further exacerbates the risk by providing no secure communication channel, leaving user credentials vulnerable to exposure.

References

https://github.com/Tymbark7372/MERCUSYS-AC12G/blob/master...

CVSS V3.1

Score:
5.9
Severity:
MEDIUM
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.