CVE-2026-36608

HIGH

Mercusys AC12G (EU) V1 Firmware AC12G(EU)_V1_200909 - Unauthenticated UPnP Port Forwarding to Admin Interface

Title source: llm

Description

Mercusys AC12G (EU) V1 router with firmware AC12G(EU)_V1_200909 allows UPnP AddPortMapping to forward external ports to the router's own admin interface by accepting its own IP (192.168.1.1) or localhost (127.0.0.1) as InternalClient. An unauthenticated LAN attacker can expose the admin panel to the internet with a single SOAP request.

References (1)

Core 1

Core References

https://github.com/Tymbark7372/MERCUSYS-AC12G/blob/master/advisories/CVE-2026-36608.md

View Writeup ZIP pw:eip

Scores

CVSS v3 8.8

EPSS 0.0018

EPSS Percentile 7.8%

Attack Vector ADJACENT_NETWORK

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact total

Details

CWE

CWE-441

Status published

Published Jun 03, 2026

Tracked Since Jun 03, 2026