CVE-2026-36603

HIGH EPSS 11.4%

Published Jun 3, 20264w ago · Modified Jun 17, 20262w ago

8.1 CVSS 3.1

High

Published Jun 3, 2026 4w ago

Last Modified Jun 17, 2026 2w ago

Description

Mercusys AC12G (EU) V1 router with firmware AC12G(EU)_V1_200909 exposes 15 of 18 UPnP IGD actions without authentication on port 1900, including AddPortMapping and GetExternalIPAddress. UPnP is enabled by default through the admin interface, allowing any unauthenticated LAN device to create arbitrary port forwarding rules and access WAN traffic statistics.

CVSS Details

Base Score

8.1

Exploitability

2.8

Impact

5.2

Vector string

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

Attack Vector Adjacent

Attack Complexity Low

Privileges Required None

User Interaction None

Scope Unchanged

Confidentiality High

Integrity High

Availability None

Threat Intelligence

EPSS Exploit Probability

11.4% percentile

Exploit & Patch Status

No Known Exploit

No Patch Available

Weaknesses 1

CWE-306 Missing Authentication for Critical Function Authentication

References 1

github.com https://github.com/Tymbark7372/MERCUSYS-AC12G/blob/master/advisories/CVE-2026-36603.md

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.